fix(frontend): prevent RangeError in TimeAdjuster and add validation to SleepButton

AGENTS.md

@@ -1,13 +1,12 @@
-# PROJECT KNOWLEDGE BASE
+# PROJECT BABY MONITOR
-
-**Generated:** 2026-04-23
-**Mode:** init-deep (create-new)
 
 ## OVERVIEW
 
-Baby Sleep Tracker - self-hosted web app for tracking infant sleep. Dual-stack monorepo: React 19/Vite 6/TypeScript frontend + Python 3.14/FastAPI backend. Optimized for Raspberry Pi 4 (ARM64).
+Baby monitor - self-hosted web app for tracking infant sleep. Dual-stack monorepo: React 19/Vite 6/TypeScript frontend + Python 3.14/FastAPI backend. Optimized for Raspberry Pi 4 (ARM64).
 
 ## STRUCTURE
+
+
 ```
 ./
 ├── frontend/           # React 19 SPA
@@ -21,6 +20,7 @@ Baby Sleep Tracker - self-hosted web app for tracking infant sleep. Dual-stack m
 │   │   └── utils/
 │   └── tests/         # e2e (Playwright), unit (Vitest)
 ├── backend/           # FastAPI + SQLModel
+│   ├── scripts/       # one-off scripts for migrations / fixes / etc
 │   ├── app/
 │   │   ├── routers/   # API endpoints
 │   │   └── utils/
@@ -40,37 +40,68 @@ Baby Sleep Tracker - self-hosted web app for tracking infant sleep. Dual-stack m
 
 ## CONVENTIONS
 
-- **Backend**: SQLModel (not pure SQLAlchemy), async aiosqlite, pytest-asyncio
+- **Backend**: SQLModel (not pure SQLAlchemy), async aiosqlite, pytest-asyncio.
-- **Frontend**: React 19, TanStack Query v5, Tailwind v4, no ESLint config (yet)
+- **Frontend**: React 19, TanStack Query v5, Tailwind v4, no ESLint config (yet).
-- **Python**: >=3.14 required, Hatch for packaging
+- **Python**: >=3.14 required. Managed via `uv` with Hatch backend for packaging.
-- **Scripts**: All scripts created in the `backend` folder must be placed in `backend/scripts/`.
+- **Scripts**: All scripts created in the backend folder must be placed explicitly in `backend/scripts/`.
-- **No CI/CD**: No .github/workflows, no Makefiles yet
+- **CI/CD**: Deployment is managed via Gitea workflows (`.gitea/` directory). Do not create `.github/` directories or Makefiles.
 
-## ANTI-PATTERNS (THIS PROJECT)
+## ANTI-PATTERNS (CRITICAL GUARDRAILS)
 
-- No type suppression (`as any`, `@ts-ignore`, `@ts-expect-error`) - type safety enforced
+- **Type Safety**: No type suppression (`as any`, `@ts-ignore`, `@ts-expect-error`). Type safety is strictly enforced.
-- No empty catch blocks - error handling required
+- **Error Handling**: No empty catch blocks. Explicit error handling/logging is required.
-- No deleting failing tests to "pass"
+- **Testing Integrity**: NEVER delete or comment out failing tests to make a suite "pass". Fix the code or update the test properly.
-- **Frontend JS Slop**: NEVER create `.js` files for the frontend. Use only TypeScript (`.ts`, `.tsx`) and write high-quality, type-safe code. Do not repeat this mistake.
+- **Frontend JS Slop**: NEVER create `.js` or `.jsx` files for the frontend. Use only TypeScript (`.ts`, `.tsx`). Write clean, type-safe code.
-- **Assumption Error**: NEVER assume the content of ANY files EVER. ALWAYS read the file to confirm. Do not rely on the name.
+- **Assumption Error**: NEVER assume the content of ANY files. ALWAYS read the target file to confirm its structure and implementation before modifying or referencing it.
 
 ## COMMANDS
 
+### Backend Development
+
 ```bash
-# Backend
+cd backend
-cd backend && uv sync
+uv sync
 uv run uvicorn app.main:app --reload
 uv run pytest
+```
 
-# Frontend
+### Frontend Development
-cd frontend && npm install
+
+```bash
+cd frontend
+npm install
 npm run dev
-# Use 'npm test' with caution as it may hang; use specific test scripts instead.
+
+# WARNING: 'npm test' may hang if run globally. Use specific file paths or vitest flags.
 npm run test
 ```
 
+## 🛑 DIRECTORY NAVIGATION & FILE DISCOVERY
+
+**Context:** This is a full-stack monorepo containing massive generated/dependency folders (`node_modules`, `dist`, `venv`, `.venv`, `__pycache__`, etc.). Unrestricted file listings will bloat your context window, crash your session, and cause severe token waste.
+
+* **NEVER use `ls -R`:** This command is strictly forbidden in this repository.
+* **Primary Discovery:** To map out files or explore the project tree, **ALWAYS use `git ls-files**`. This is your default command and ensures you only interact with human-written source code.
+* **Structural Context:** If you explicitly need a visual directory layout to understand architecture, use `tree` appended with the mandatory ignore flags:
+```bash
+tree -I 'node_modules|.git|dist|build|__pycache__|venv|.venv|env|.pytest_cache|.mypy_cache|.ruff_cache|*.egg-info'
+
+```
+
+
+* **Searching Code:** If you need to search for text or code blocks across the repo, **ALWAYS use `git grep "search_term"**` instead of standard `grep -r` to avoid crawling ignored or minified assets.
+
+## 🧠 TASK DELEGATION & CONTEXT PRESERVATION
+
+**Context:** The main OpenCode agent context window is our most critical resource. Executing complex tasks, debugging cross-file issues, or writing massive features directly in the main thread causes severe context bloat, leading to code hallucinations and dropped instructions.
+
+* **Delegate Aggressively:** For any complex implementation, structural change, or task larger than a single file edit, you **MUST spawn a sub-agent**. Act strictly as the architectural orchestrator; let sub-agents handle the iterative coding labor.
+* **Scope Narrowly:** Give sub-agents highly specific, isolated, and atomic objectives (e.g., *"Read `backend/app/routers/auth.py` and summarize endpoints"* or *"Write a unit test for the frontend sleep tracker component"*).
+* **Strict Summarization:** Sub-agents are **STRICTLY FORBIDDEN** from passing raw terminal dumps, unedited file blocks, or their internal step-by-step logs back to the main thread.
+* **Return Format:** Sub-agents must return *only* clear, actionable results back to the orchestrator: a concise summary of findings, the exact lines of code that require modification, or direct confirmation of a successful execution.
+
 ## NOTES
 
-- Entry point: `frontend/src/main.tsx` + `backend/app/main.py`
+* **Entry Points:** `frontend/src/main.tsx` (Frontend) & `backend/app/main.py` (Backend).
-- DB: SQLite via aiosqlite (async-first backend)
+* **Database:** Local SQLite managed via `aiosqlite` for an entirely async-first data layer.
-- Build: Docker for ARM64 Raspberry Pi deployment
+* **Target Architecture:** Built specifically for ARM64 deployment on a Raspberry Pi 4 via Docker.

diff.md

@@ -0,0 +1,247 @@
+diff --git a/frontend/src/components/stats/SessionList.tsx b/frontend/src/components/stats/SessionList.tsx
+index 374e41c..2bd6ea7 100644
+--- a/frontend/src/components/stats/SessionList.tsx
++++ b/frontend/src/components/stats/SessionList.tsx
+@@ -1,15 +1,29 @@
+ import React, { useState } from 'react';
+ import { useSessions } from '../../hooks/useSleepSession';
++import { useSettings } from '../../hooks/useSettings';
++import { Pagination } from './Pagination';
+ import { Edit2, Check, X, Trash2 } from 'lucide-react';
+ import type { SleepSessionRead } from '../../types';
+ import { formatDateTime, toLocalDatetimeInputValue, getDurationMinutes, formatMinutes } from '../../utils/time';
+ 
+ export function SessionList() {
+   const { sessions, isLoading, updateSession, deleteSession, isDeleting } = useSessions();
++  const { settings } = useSettings();
++  const sessionsPerPage = settings.sessionsPerPage;
++
++  const [currentPage, setCurrentPage] = useState(1);
+   const [editingId, setEditingId] = useState<number | null>(null);
+   const [editStart, setEditStart] = useState<string>('');
+   const [editEnd, setEditEnd] = useState<string>('');
+ 
++  const totalPages = Math.ceil(sessions.length / sessionsPerPage);
++  const clampedPage = Math.max(1, Math.min(currentPage, totalPages || 1));
++
++  const paginatedSessions = sessions.slice(
++    (clampedPage - 1) * sessionsPerPage,
++    clampedPage * sessionsPerPage
++  );
++
+   if (isLoading) return <div className="text-center p-4">Loading sessions...</div>;
+   if (!sessions.length) return <div className="text-center p-4 text-gray-500">No sessions recorded.</div>;
+ 
+@@ -55,7 +69,7 @@ export function SessionList() {
+     <div className="bg-white p-4 rounded-xl shadow-sm border border-gray-200">
+       <h3 className="text-lg font-semibold mb-4 text-gray-800">Sleep Sessions</h3>
+       <div className="space-y-2">
+-        {sessions.map((s) => (
++        {paginatedSessions.map((s) => (
+           <div key={s.id} className="border-b border-gray-100 last:border-0 py-3 sm:py-2">
+             {editingId === s.id ? (
+               <div className="flex flex-col space-y-3 py-1">
+@@ -140,6 +154,13 @@ export function SessionList() {
+           </div>
+         ))}
+       </div>
++      {sessions.length > sessionsPerPage && (
++        <Pagination 
++          currentPage={clampedPage} 
++          totalPages={totalPages} 
++          onPageChange={setCurrentPage} 
++        />
++      )}
+     </div>
+   );
+ }
+diff --git a/frontend/src/components/stats/SettingsPopover.tsx b/frontend/src/components/stats/SettingsPopover.tsx
+index 005a302..8031392 100644
+--- a/frontend/src/components/stats/SettingsPopover.tsx
++++ b/frontend/src/components/stats/SettingsPopover.tsx
+@@ -6,15 +6,17 @@ interface SettingsPopoverProps {
+   dayEnd: string;
+   wakeupRef: string;
+   bedtimeRef: string;
+-  onSave: (settings: { dayStart: string; dayEnd: string; wakeupRef: string; bedtimeRef: string }) => void;
++  sessionsPerPage: number;
++  onSave: (settings: { dayStart: string; dayEnd: string; wakeupRef: string; bedtimeRef: string; sessionsPerPage: number }) => void;
+ }
+ 
+-export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSave }: SettingsPopoverProps) {
++export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, sessionsPerPage, onSave }: SettingsPopoverProps) {
+   const [isOpen, setIsOpen] = useState(false);
+   const [localDayStart, setLocalDayStart] = useState(dayStart);
+   const [localDayEnd, setLocalDayEnd] = useState(dayEnd);
+   const [localWakeupRef, setLocalWakeupRef] = useState(wakeupRef);
+   const [localBedtimeRef, setLocalBedtimeRef] = useState(bedtimeRef);
++  const [localSessionsPerPage, setLocalSessionsPerPage] = useState(sessionsPerPage);
+   const popoverRef = useRef<HTMLDivElement>(null);
+ 
+   useEffect(() => {
+@@ -22,7 +24,8 @@ export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSav
+     setLocalDayEnd(dayEnd);
+     setLocalWakeupRef(wakeupRef);
+     setLocalBedtimeRef(bedtimeRef);
+-  }, [dayStart, dayEnd, wakeupRef, bedtimeRef]);
++    setLocalSessionsPerPage(sessionsPerPage);
++  }, [dayStart, dayEnd, wakeupRef, bedtimeRef, sessionsPerPage]);
+ 
+   useEffect(() => {
+     const handleClickOutside = (e: MouseEvent) => {
+@@ -42,6 +45,7 @@ export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSav
+       dayEnd: localDayEnd,
+       wakeupRef: localWakeupRef,
+       bedtimeRef: localBedtimeRef,
++      sessionsPerPage: localSessionsPerPage,
+     });
+     setIsOpen(false);
+   };
+@@ -65,44 +69,58 @@ export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSav
+           
+           <div className="space-y-3">
+             <div>
+-<label htmlFor="day-start" className="block text-xs text-gray-500 mb-1">Day starts (HH:MM)</label>
+-<input
+-  id="day-start"
+-  type="time"
+-  value={localDayStart}
+-  onChange={(e) => setLocalDayStart(e.target.value)}
+-  className="w-full p-2 border rounded-md text-sm"
+-/>
++              <label htmlFor="day-start" className="block text-xs text-gray-500 mb-1">Day starts (HH:MM)</label>
++              <input
++                id="day-start"
++                type="time"
++                value={localDayStart}
++                onChange={(e) => setLocalDayStart(e.target.value)}
++                className="w-full p-2 border rounded-md text-sm"
++              />
+             </div>
+             <div>
+-<label htmlFor="day-end" className="block text-xs text-gray-500 mb-1">Day ends (HH:MM)</label>
+-<input
+-  id="day-end"
+-  type="time"
+-  value={localDayEnd}
+-  onChange={(e) => setLocalDayEnd(e.target.value)}
+-  className="w-full p-2 border rounded-md text-sm"
+-/>
++              <label htmlFor="day-end" className="block text-xs text-gray-500 mb-1">Day ends (HH:MM)</label>
++              <input
++                id="day-end"
++                type="time"
++                value={localDayEnd}
++                onChange={(e) => setLocalDayEnd(e.target.value)}
++                className="w-full p-2 border rounded-md text-sm"
++              />
+             </div>
+             <div>
+-<label htmlFor="wakeup-ref" className="block text-xs text-gray-500 mb-1">Wakeup ref (HH:MM)</label>
+-<input
+-  id="wakeup-ref"
+-  type="time"
+-  value={localWakeupRef}
+-  onChange={(e) => setLocalWakeupRef(e.target.value)}
+-  className="w-full p-2 border rounded-md text-sm"
+-/>
++              <label htmlFor="wakeup-ref" className="block text-xs text-gray-500 mb-1">Wakeup ref (HH:MM)</label>
++              <input
++                id="wakeup-ref"
++                type="time"
++                value={localWakeupRef}
++                onChange={(e) => setLocalWakeupRef(e.target.value)}
++                className="w-full p-2 border rounded-md text-sm"
++              />
+             </div>
+             <div>
+-<label htmlFor="bedtime-ref" className="block text-xs text-gray-500 mb-1">Bedtime ref (HH:MM)</label>
+-<input
+-  id="bedtime-ref"
+-  type="time"
+-  value={localBedtimeRef}
+-  onChange={(e) => setLocalBedtimeRef(e.target.value)}
+-  className="w-full p-2 border rounded-md text-sm"
+-/>
++              <label htmlFor="bedtime-ref" className="block text-xs text-gray-500 mb-1">Bedtime ref (HH:MM)</label>
++              <input
++                id="bedtime-ref"
++                type="time"
++                value={localBedtimeRef}
++                onChange={(e) => setLocalBedtimeRef(e.target.value)}
++                className="w-full p-2 border rounded-md text-sm"
++              />
++            </div>
++            <div>
++              <label htmlFor="sessions-per-page" className="block text-xs text-gray-500 mb-1">Results per page</label>
++              <select
++                id="sessions-per-page"
++                value={localSessionsPerPage}
++                onChange={(e) => setLocalSessionsPerPage(Number(e.target.value))}
++                className="w-full p-2 border rounded-md text-sm"
++              >
++                <option value={5}>5</option>
++                <option value={10}>10</option>
++                <option value={25}>25</option>
++                <option value={50}>50</option>
++              </select>
+             </div>
+           </div>
+ 
+diff --git a/frontend/src/components/stats/StatsPage.tsx b/frontend/src/components/stats/StatsPage.tsx
+index 2516d55..e3518c8 100644
+--- a/frontend/src/components/stats/StatsPage.tsx
++++ b/frontend/src/components/stats/StatsPage.tsx
+@@ -27,18 +27,20 @@ const StatsPage: React.FC = () => {
+           <h2 className="text-3xl font-extrabold text-slate-900 tracking-tight">Statistics</h2>
+           <p className="text-slate-500 text-sm mt-1">Overview of sleep patterns and trends</p>
+         </div>
+-        <SettingsPopover
+-          dayStart={settings.dayStart}
+-          dayEnd={settings.dayEnd}
+-          wakeupRef={settings.wakeupRef}
+-          bedtimeRef={settings.bedtimeRef}
+-          onSave={(s) => {
+-            update('dayStart', s.dayStart);
+-            update('dayEnd', s.dayEnd);
+-            update('wakeupRef', s.wakeupRef);
+-            update('bedtimeRef', s.bedtimeRef);
+-          }}
+-        />
++         <SettingsPopover
++           dayStart={settings.dayStart}
++           dayEnd={settings.dayEnd}
++           wakeupRef={settings.wakeupRef}
++           bedtimeRef={settings.bedtimeRef}
++           sessionsPerPage={settings.sessionsPerPage}
++           onSave={(s) => {
++             update('dayStart', s.dayStart);
++             update('dayEnd', s.dayEnd);
++             update('wakeupRef', s.wakeupRef);
++             update('bedtimeRef', s.bedtimeRef);
++             update('sessionsPerPage', s.sessionsPerPage);
++           }}
++         />
+       </div>
+ 
+       <div className="bg-white p-6 rounded-[2rem] shadow-md border border-gray-100">
+diff --git a/frontend/src/hooks/useSettings.ts b/frontend/src/hooks/useSettings.ts
+index c587fb3..d95899b 100644
+--- a/frontend/src/hooks/useSettings.ts
++++ b/frontend/src/hooks/useSettings.ts
+@@ -8,6 +8,7 @@ interface Settings {
+   wakeupRef: string;
+   bedtimeRef: string;
+   statsInterval: number;
++  sessionsPerPage: number;
+ }
+ 
+ const DEFAULT_SETTINGS: Settings = {
+@@ -16,6 +17,7 @@ const DEFAULT_SETTINGS: Settings = {
+   wakeupRef: '04:00',
+   bedtimeRef: '19:00',
+   statsInterval: 7,
++  sessionsPerPage: 10,
+ };
+ 
+ export function useSettings() {

frontend/src/components/stats/Pagination.tsx

@@ -0,0 +1,104 @@
+import React from 'react';
+import { ChevronLeft, ChevronRight, MoreHorizontal } from 'lucide-react';
+
+interface PaginationProps {
+  currentPage: number;
+  totalPages: number;
+  onPageChange: (page: number) => void;
+}
+
+export function Pagination({ currentPage, totalPages, onPageChange }: PaginationProps) {
+  if (totalPages <= 1) return null;
+
+  const getPageNumbers = () => {
+    const pages: (number | string)[] = [];
+    const maxVisiblePages = 5;
+
+    if (totalPages <= maxVisiblePages) {
+      for (let i = 1; i <= totalPages; i++) {
+        pages.push(i);
+      }
+    } else {
+      // Always include first page
+      pages.push(1);
+
+      if (currentPage > 3) {
+        pages.push('...');
+      }
+
+      // Calculate middle pages
+      const start = Math.max(2, currentPage - 1);
+      const end = Math.min(totalPages - 1, currentPage + 1);
+
+      for (let i = start; i <= end; i++) {
+        if (!pages.includes(i)) {
+          pages.push(i);
+        }
+      }
+
+      if (currentPage < totalPages - 2) {
+        pages.push('...');
+      }
+
+      // Always include last page
+      if (!pages.includes(totalPages)) {
+        pages.push(totalPages);
+      }
+    }
+
+    return pages;
+  };
+
+  const pages = getPageNumbers();
+
+  return (
+    <div data-testid="pagination" className="flex items-center justify-center gap-1 mt-6 py-4">
+      <button
+        onClick={() => onPageChange(Math.max(1, currentPage - 1))}
+        disabled={currentPage === 1}
+        className="p-2 rounded-lg hover:bg-gray-100 disabled:opacity-30 disabled:cursor-not-allowed transition-colors text-gray-600"
+        aria-label="Previous page"
+      >
+        <ChevronLeft size={20} />
+      </button>
+
+      <div className="flex items-center gap-1">
+        {pages.map((page, idx) => {
+          if (page === '...') {
+            return (
+              <div key={`ellipsis-${idx}`} className="px-2 text-gray-400">
+                <MoreHorizontal size={16} />
+              </div>
+            );
+          }
+
+          const pageNum = page as number;
+          const isActive = currentPage === pageNum;
+
+          return (
+            <button
+              key={pageNum}
+              onClick={() => onPageChange(pageNum)}
+              className={`min-w-[36px] h-9 px-2 rounded-lg text-sm font-medium transition-all ${
+                isActive
+                  ? 'bg-blue-600 text-white shadow-sm'
+                  : 'text-gray-600 hover:bg-gray-100'
+              }`}
+            >
+              {pageNum}
+            </button>
+          );
+        })}
+      </div>
+
+      <button
+        onClick={() => onPageChange(Math.min(totalPages, currentPage + 1))}
+        disabled={currentPage === totalPages}
+        className="p-2 rounded-lg hover:bg-gray-100 disabled:opacity-30 disabled:cursor-not-allowed transition-colors text-gray-600"
+        aria-label="Next page"
+      >
+        <ChevronRight size={20} />
+      </button>
+    </div>
+  );
+}

frontend/src/components/stats/SessionList.tsx

@@ -1,15 +1,29 @@
 import React, { useState } from 'react';
 import { useSessions } from '../../hooks/useSleepSession';
+import { useSettings } from '../../hooks/useSettings';
+import { Pagination } from './Pagination';
 import { Edit2, Check, X, Trash2 } from 'lucide-react';
 import type { SleepSessionRead } from '../../types';
 import { formatDateTime, toLocalDatetimeInputValue, getDurationMinutes, formatMinutes } from '../../utils/time';
 
 export function SessionList() {
   const { sessions, isLoading, updateSession, deleteSession, isDeleting } = useSessions();
+  const { settings } = useSettings();
+  const sessionsPerPage = settings.sessionsPerPage;
+
+  const [currentPage, setCurrentPage] = useState(1);
   const [editingId, setEditingId] = useState<number | null>(null);
   const [editStart, setEditStart] = useState<string>('');
   const [editEnd, setEditEnd] = useState<string>('');
 
+  const totalPages = Math.ceil(sessions.length / sessionsPerPage);
+  const clampedPage = Math.max(1, Math.min(currentPage, totalPages || 1));
+
+  const paginatedSessions = sessions.slice(
+    (clampedPage - 1) * sessionsPerPage,
+    clampedPage * sessionsPerPage
+  );
+
   if (isLoading) return <div className="text-center p-4">Loading sessions...</div>;
   if (!sessions.length) return <div className="text-center p-4 text-gray-500">No sessions recorded.</div>;
 
@@ -52,10 +66,10 @@ export function SessionList() {
   };
 
   return (
-    <div className="bg-white p-4 rounded-xl shadow-sm border border-gray-200">
+    <div className="session-list bg-white p-4 rounded-xl shadow-sm border border-gray-200">
       <h3 className="text-lg font-semibold mb-4 text-gray-800">Sleep Sessions</h3>
       <div className="space-y-2">
-        {sessions.map((s) => (
+        {paginatedSessions.map((s) => (
           <div key={s.id} className="border-b border-gray-100 last:border-0 py-3 sm:py-2">
             {editingId === s.id ? (
               <div className="flex flex-col space-y-3 py-1">
@@ -140,6 +154,13 @@ export function SessionList() {
           </div>
         ))}
       </div>
+      {sessions.length > sessionsPerPage && (
+        <Pagination 
+          currentPage={clampedPage} 
+          totalPages={totalPages} 
+          onPageChange={setCurrentPage} 
+        />
+      )}
     </div>
   );
 }

frontend/src/components/stats/SettingsPopover.tsx

@@ -6,15 +6,17 @@ interface SettingsPopoverProps {
   dayEnd: string;
   wakeupRef: string;
   bedtimeRef: string;
-  onSave: (settings: { dayStart: string; dayEnd: string; wakeupRef: string; bedtimeRef: string }) => void;
+  sessionsPerPage: number;
+  onSave: (settings: { dayStart: string; dayEnd: string; wakeupRef: string; bedtimeRef: string; sessionsPerPage: number }) => void;
 }
 
-export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSave }: SettingsPopoverProps) {
+export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, sessionsPerPage, onSave }: SettingsPopoverProps) {
   const [isOpen, setIsOpen] = useState(false);
   const [localDayStart, setLocalDayStart] = useState(dayStart);
   const [localDayEnd, setLocalDayEnd] = useState(dayEnd);
   const [localWakeupRef, setLocalWakeupRef] = useState(wakeupRef);
   const [localBedtimeRef, setLocalBedtimeRef] = useState(bedtimeRef);
+  const [localSessionsPerPage, setLocalSessionsPerPage] = useState(sessionsPerPage);
   const popoverRef = useRef<HTMLDivElement>(null);
 
   useEffect(() => {
@@ -22,7 +24,8 @@ export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSav
     setLocalDayEnd(dayEnd);
     setLocalWakeupRef(wakeupRef);
     setLocalBedtimeRef(bedtimeRef);
-  }, [dayStart, dayEnd, wakeupRef, bedtimeRef]);
+    setLocalSessionsPerPage(sessionsPerPage);
+  }, [dayStart, dayEnd, wakeupRef, bedtimeRef, sessionsPerPage]);
 
   useEffect(() => {
     const handleClickOutside = (e: MouseEvent) => {
@@ -42,6 +45,7 @@ export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSav
       dayEnd: localDayEnd,
       wakeupRef: localWakeupRef,
       bedtimeRef: localBedtimeRef,
+      sessionsPerPage: localSessionsPerPage,
     });
     setIsOpen(false);
   };
@@ -65,44 +69,58 @@ export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSav
           
           <div className="space-y-3">
             <div>
-<label htmlFor="day-start" className="block text-xs text-gray-500 mb-1">Day starts (HH:MM)</label>
+              <label htmlFor="day-start" className="block text-xs text-gray-500 mb-1">Day starts (HH:MM)</label>
-<input
+              <input
                 id="day-start"
                 type="time"
                 value={localDayStart}
                 onChange={(e) => setLocalDayStart(e.target.value)}
                 className="w-full p-2 border rounded-md text-sm"
-/>
+              />
             </div>
             <div>
-<label htmlFor="day-end" className="block text-xs text-gray-500 mb-1">Day ends (HH:MM)</label>
+              <label htmlFor="day-end" className="block text-xs text-gray-500 mb-1">Day ends (HH:MM)</label>
-<input
+              <input
                 id="day-end"
                 type="time"
                 value={localDayEnd}
                 onChange={(e) => setLocalDayEnd(e.target.value)}
                 className="w-full p-2 border rounded-md text-sm"
-/>
+              />
             </div>
             <div>
-<label htmlFor="wakeup-ref" className="block text-xs text-gray-500 mb-1">Wakeup ref (HH:MM)</label>
+              <label htmlFor="wakeup-ref" className="block text-xs text-gray-500 mb-1">Wakeup ref (HH:MM)</label>
-<input
+              <input
                 id="wakeup-ref"
                 type="time"
                 value={localWakeupRef}
                 onChange={(e) => setLocalWakeupRef(e.target.value)}
                 className="w-full p-2 border rounded-md text-sm"
-/>
+              />
             </div>
             <div>
-<label htmlFor="bedtime-ref" className="block text-xs text-gray-500 mb-1">Bedtime ref (HH:MM)</label>
+              <label htmlFor="bedtime-ref" className="block text-xs text-gray-500 mb-1">Bedtime ref (HH:MM)</label>
-<input
+              <input
                 id="bedtime-ref"
                 type="time"
                 value={localBedtimeRef}
                 onChange={(e) => setLocalBedtimeRef(e.target.value)}
                 className="w-full p-2 border rounded-md text-sm"
-/>
+              />
+            </div>
+            <div>
+              <label htmlFor="sessions-per-page" className="block text-xs text-gray-500 mb-1">Results per page</label>
+              <select
+                id="sessions-per-page"
+                value={localSessionsPerPage}
+                onChange={(e) => setLocalSessionsPerPage(Number(e.target.value))}
+                className="w-full p-2 border rounded-md text-sm"
+              >
+                <option value={5}>5</option>
+                <option value={10}>10</option>
+                <option value={25}>25</option>
+                <option value={50}>50</option>
+              </select>
             </div>
           </div>
 

frontend/src/components/stats/StatsPage.tsx

@@ -32,11 +32,13 @@ const StatsPage: React.FC = () => {
            dayEnd={settings.dayEnd}
            wakeupRef={settings.wakeupRef}
            bedtimeRef={settings.bedtimeRef}
+           sessionsPerPage={settings.sessionsPerPage}
            onSave={(s) => {
              update('dayStart', s.dayStart);
              update('dayEnd', s.dayEnd);
              update('wakeupRef', s.wakeupRef);
              update('bedtimeRef', s.bedtimeRef);
+             update('sessionsPerPage', s.sessionsPerPage);
            }}
          />
       </div>

frontend/src/components/tracker/SleepButton.tsx

@@ -10,6 +10,10 @@ const SleepButton: React.FC<SleepButtonProps> = ({ time }) => {
   const isSleeping = !!activeSession;
 
   const handleClick = async () => {
+    if (!time) {
+      alert('Please select a valid time.');
+      return;
+    }
     try {
       if (isSleeping && activeSession?.id) {
         await endSession({ sessionId: activeSession.id, endTime: time });

frontend/src/hooks/SettingsProvider.tsx

@@ -0,0 +1,57 @@
+import React, { createContext, useContext, useState, useEffect, ReactNode } from 'react';
+
+const STORAGE_KEY = 'baby-sleep-settings';
+
+export interface Settings {
+  dayStart: string;
+  dayEnd: string;
+  wakeupRef: string;
+  bedtimeRef: string;
+  statsInterval: number;
+  sessionsPerPage: number;
+}
+
+interface SettingsContextType {
+  settings: Settings;
+  update: (key: keyof Settings, value: string | number) => void;
+}
+
+export const SettingsContext = createContext<SettingsContextType | undefined>(undefined);
+
+const DEFAULT_SETTINGS: Settings = {
+  dayStart: '07:00',
+  dayEnd: '20:00',
+  wakeupRef: '04:00',
+  bedtimeRef: '19:00',
+  statsInterval: 7,
+  sessionsPerPage: 10,
+};
+
+export function SettingsProvider({ children }: { children: ReactNode }) {
+  const [settings, setSettings] = useState<Settings>(() => {
+    if (typeof window === 'undefined') return DEFAULT_SETTINGS;
+    const stored = localStorage.getItem(STORAGE_KEY);
+    if (stored) {
+      try {
+        return { ...DEFAULT_SETTINGS, ...JSON.parse(stored) };
+      } catch {
+        return DEFAULT_SETTINGS;
+      }
+    }
+    return DEFAULT_SETTINGS;
+  });
+
+  useEffect(() => {
+    localStorage.setItem(STORAGE_KEY, JSON.stringify(settings));
+  }, [settings]);
+
+  const update = (key: keyof Settings, value: string | number) => {
+    setSettings((prev) => ({ ...prev, [key]: value }));
+  };
+
+  return (
+    <SettingsContext.Provider value={{ settings, update }}>
+      {children}
+    </SettingsContext.Provider>
+  );
+}

frontend/src/hooks/useSettings.ts

@@ -1,44 +1,10 @@
-import { useState, useEffect } from 'react';
+import { useContext } from 'react';
-
+import { SettingsContext, Settings } from './SettingsProvider';
-const STORAGE_KEY = 'baby-sleep-settings';
-
-interface Settings {
-  dayStart: string;
-  dayEnd: string;
-  wakeupRef: string;
-  bedtimeRef: string;
-  statsInterval: number;
-}
-
-const DEFAULT_SETTINGS: Settings = {
-  dayStart: '07:00',
-  dayEnd: '20:00',
-  wakeupRef: '04:00',
-  bedtimeRef: '19:00',
-  statsInterval: 7,
-};
 
 export function useSettings() {
-  const [settings, setSettings] = useState<Settings>(() => {
+  const context = useContext(SettingsContext);
-    if (typeof window === 'undefined') return DEFAULT_SETTINGS;
+  if (context === undefined) {
-    const stored = localStorage.getItem(STORAGE_KEY);
+    throw new Error('useSettings must be used within a SettingsProvider');
-    if (stored) {
-      try {
-        return { ...DEFAULT_SETTINGS, ...JSON.parse(stored) };
-      } catch {
-        return DEFAULT_SETTINGS;
   }
-    }
+  return context;
-    return DEFAULT_SETTINGS;
-  });
-
-  useEffect(() => {
-    localStorage.setItem(STORAGE_KEY, JSON.stringify(settings));
-  }, [settings]);
-
-  const update = (key: keyof Settings, value: string | number) => {
-    setSettings((prev) => ({ ...prev, [key]: value }));
-  };
-
-  return { settings, update };
 }

frontend/src/main.tsx

@@ -2,14 +2,17 @@ import React from 'react'
 import ReactDOM from 'react-dom/client'
 import './index.css'
 import App from './App'
-import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { SettingsProvider } from './hooks/SettingsProvider';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
 
 const queryClient = new QueryClient()
 
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
     <QueryClientProvider client={queryClient}>
+      <SettingsProvider>
         <App />
+      </SettingsProvider>
     </QueryClientProvider>
   </React.StrictMode>,
 )

frontend/src/utils/time.ts

@@ -90,6 +90,9 @@ export function formatDateTime(date: Date | string): string {
  */
 export function toUTCFromLocalInput(inputValue: string): string {
   const d = new Date(inputValue);
+  if (isNaN(d.getTime())) {
+    return "";
+  }
   return d.toISOString();
 }
 

frontend/tests/e2e/pagination.spec.ts

@@ -0,0 +1,127 @@
+import { test, expect } from '@playwright/test';
+
+test.describe('Pagination', () => {
+  test.beforeEach(async ({ page }) => {
+    // Monitor network requests to see if our mock is hit
+    page.on('request', request => console.log('>>', request.method(), request.url()));
+    page.on('response', response => console.log('<<', response.status(), response.url()));
+
+    // Mock the sessions API
+    await page.route('**/api/sessions', async (route) => {
+      const mockSessions = Array.from({ length: 15 }, (_, i) => ({
+        id: i + 1,
+        start_time: new Date(2024, 0, 1 + i).toISOString(),
+        end_time: new Date(2024, 0, 1 + i, 8, 0).toISOString(),
+        notes: null,
+        created_at: new Date().toISOString(),
+        updated_at: new Date().toISOString(),
+      }));
+      await route.fulfill({
+        status: 200,
+        contentType: 'application/json',
+        body: JSON.stringify({ sessions: mockSessions, total: 15 }),
+      });
+    });
+
+    // Mock other stats APIs to prevent crashes from accessing undefined properties
+    await page.route(/\/api\/stats\/.*/, async (route) => {
+      const url = route.request().url();
+      let body = {};
+
+      if (url.includes('summary')) {
+        body = {
+          total_sleeps: 10,
+          avg_sleeps_per_day: 2.5,
+          total_sleeps_all_time: 100,
+          avg_sleeps_per_day_all_time: 2.0,
+        };
+      } else if (url.includes('daily-summary')) {
+        body = {
+          days: [
+            { date: '2024-01-01', total_minutes: 480, day_minutes: 240, night_minutes: 240 },
+          ],
+        };
+      } else if (url.includes('timetable')) {
+        body = {
+          slots: [],
+        };
+      } else if (url.includes('wake-sleep-times')) {
+        body = {
+          days: [
+            { date: '2024-01-01', wakeup_minutes: 480, bedtime_minutes: 1200 },
+          ],
+        };
+      }
+
+      await route.fulfill({
+        status: 200,
+        contentType: 'application/json',
+        body: JSON.stringify(body),
+      });
+    });
+
+    await page.goto('http://localhost:5173/stats');
+  });
+
+  test('Pagination component is visible when sessions exceed page size', async ({ page }) => {
+    // Wait for one of the mocked dates to appear to ensure data is loaded
+    await expect(page.locator('body')).toContainText('2024-01-01', { timeout: 10000 });
+    await page.screenshot({ path: 'screenshots/pagination_visible.png' });
+
+    const pagination = page.getByTestId('pagination');
+    await expect(pagination).toBeVisible();
+
+    // Use a more specific selector for the first page button
+    await expect(page.getByTestId('pagination').getByRole('button', { name: '1' })).toBeVisible();
+  });
+
+  test('Changing results per page in settings updates the list', async ({ page }) => {
+    // Wait for data to load first
+    await expect(page.locator('body')).toContainText('2024-01-01', { timeout: 10000 });
+    await page.screenshot({ path: 'screenshots/before_settings_change.png' });
+
+    // Open Settings
+    await page.getByRole('button', { name: /Settings/i }).click();
+    await expect(page.locator('text=Results per page')).toBeVisible();
+
+    // Change to 5
+    await page.getByLabel(/Results per page/i).selectOption('5');
+    await page.getByRole('button', { name: /Save/i }).click();
+    
+    // Wait for the UI to update and settings to be saved
+    await page.waitForTimeout(2000);
+
+    await page.screenshot({ path: 'screenshots/after_settings_change.png' });
+
+    // Verify sessions per page is 5 (only 5 should be visible)
+    const sessionRows = page.locator('.session-list .border-b');
+    await expect(sessionRows).toHaveCount(5);
+
+    // Verify settings is saved in localStorage
+    const localStorage = await page.evaluate(() => {
+      return window.localStorage.getItem('baby-sleep-settings');
+    });
+    expect(localStorage).toContain('"sessionsPerPage":5');
+  });
+
+  test('Navigating through pages works', async ({ page }) => {
+    // Wait for data to load first
+    await expect(page.locator('body')).toContainText('2024-01-01', { timeout: 10000 });
+    
+    // Set to 5 via settings first
+    await page.getByRole('button', { name: /Settings/i }).click();
+    await page.getByLabel(/Results per page/i).selectOption('5');
+    await page.getByRole('button', { name: /Save/i }).click();
+    await page.waitForTimeout(2000);
+
+    const nextButton = page.getByRole('button', { name: /Next/i });
+    await expect(nextButton).toBeVisible();
+
+    await nextButton.click();
+    await page.waitForTimeout(1000);
+
+    // Should now show sessions from index 5 to 9 (if total is 15)
+    // Mocked start_time for i=5 is 2024-01-06
+    await expect(page.locator('.text-gray-900').filter({ hasText: '2024-01-06' }).first()).toBeVisible();
+  });
+});

frontend/tests/unit/SleepButton.test.tsx

@@ -70,4 +70,20 @@ describe('SleepButton', () => {
 
     await waitFor(() => expect(endSessionMock).toHaveBeenCalled());
   });
+
+  it('shows alert when time is invalid', async () => {
+    const alertSpy = vi.spyOn(window, 'alert').mockImplementation(() => {});
+    (useSleepSession as any).mockReturnValue({
+      activeSession: null,
+      isCreating: false,
+      isEnding: false,
+    });
+
+    renderWithProviders(<SleepButton time="" />);
+    const button = screen.getByRole('button', { name: /Start Sleep/i });
+    fireEvent.click(button);
+
+    expect(alertSpy).toHaveBeenCalledWith('Please select a valid time.');
+    alertSpy.mockRestore();
+  });
 });

frontend/tests/unit/TimeAdjuster.test.tsx

@@ -29,4 +29,18 @@ describe('TimeAdjuster', () => {
     fireEvent.click(resetButton);
     expect(handleChange).toHaveBeenCalled();
   });
+
+  it('handles invalid date input gracefully (returns empty string)', async () => {
+    // Since we changed the implementation, it should no longer throw.
+    // We can't easily test the useEffect error anymore because it doesn't throw,
+    // but we can check if onTimeChange is called with "" for invalid input.
+    const handleChange = vi.fn();
+    const { container } = render(<TimeAdjuster onTimeChange={handleChange} />);
+    const input = container.querySelector('input');
+
+    fireEvent.change(input!, { target: { value: '2026-06-0' } });
+    // We might need to wait for the effect
+    await new Promise((r) => setTimeout(r, 0));
+    expect(handleChange).toHaveBeenCalledWith("");
+  });
 });

frontend/tests/unit/time.test.ts

@@ -12,6 +12,7 @@ import {
   adjustForTimezone,
   getLocalOffsetFromReference,
   formatDateTime,
+  toUTCFromLocalInput,
 } from '../../src/utils/time';
 
 describe('formatMinutesAfter', () => {
@@ -152,3 +153,18 @@ describe('getLocalOffsetFromReference', () => {
     expect(offset).toBe(localMins - refMins);
   });
 });
+
+describe('toUTCFromLocalInput', () => {
+  it('converts valid datetime-local string to ISO UTC string', () => {
+    const input = '2024-01-15T10:00';
+    // This is tricky because it depends on local timezone. 
+    // But we just want to see if it works for a valid input.
+    const result = toUTCFromLocalInput(input);
+    expect(result).toMatch(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/);
+  });
+
+  it('returns empty string on invalid datetime-local string', () => {
+    expect(toUTCFromLocalInput('2026-06-0')).toBe('');
+  });
+});
+

plan.md

@@ -0,0 +1,351 @@
+# Proposed Implementation Plan
+
+## Phase 1: Settings Update
+*   **`frontend/src/hooks/useSettings.ts`**: Add `sessionsPerPage` to the settings state and define a default value (e.g., 10).
+*   **`frontend/src/components/stats/SettingsPopover.tsx`**: 
+    *   Update the props and local state to include `sessionsPerPage`.
+    *   Add a dropdown in the settings UI for selecting "Results per page" (e.g., 5, 10, 25, 50).
+*   **`frontend/src/components/stats/StatsPage.tsx`**: Update the `onSave` handler to persist the new `sessionsPerPage` setting.
+
+## Phase 2: Pagination UI and Logic
+*   **`frontend/src/components/stats/Pagination.tsx` (New Component)**: Implement a "Google-style" pagination component with `Previous`, page numbers, and `Next` buttons.
+*   **`frontend/src/components/stats/SessionList.tsx`**: 
+    *   Integrate `useSettings` to fetch the selected page size.
+    *   Implement local pagination logic (managing `currentPage`).
+    *   Slice the session data to show only the current page's items.
+    *   Render the new `Pagination` component at the bottom of the list.
+
+## Phase 3: Verification
+*   Verify that changing "Results per page" in Settings correctly updates the list.
+*   Confirm pagination navigation (Prev/Next/Numbers) works as expected and handles edge cases (e.g., first/last page).
+
+I will use multiple sub-agents to execute these tasks in parallel.
+
+---
+
+The user wants to implement client-side pagination for "Sleep Sessions".
+Plan:
+1. Update `useSettings` to include `sessionsPerPage`.
+2. Update `SettingsPopover` to allow users to change `sessionsPerPage`.
+3. Update `StatsPage`'s `onSave` in `SettingsPopover` to include the new setting.
+4. Create a new `Pagination` component.
+5. Update `SessionList` to use pagination logic and the new component.
+6. Verify with Playwright and screenshots.
+
+I'll start by using `todowrite` to track progress.
+Then I will launch sub-agents.
+
+Sub-agents:
+1. `explore` (or `general`) for Phase 1 (Settings).
+2. `general` for Phase 2 (Pagination component and SessionList logic).
+3. `general` for Phase 3 (Playwright verification).
+
+Wait, the user said "use as many sub-agents as possible". I'll split it.
+
+Task 1: Update settings (useSettings, SettingsPopover, StatsPage).
+Task 2: Implement Pagination component and integrate it into SessionList.
+Task 3: Write Playwright tests to verify functionality and take screenshots.
+
+Let's start with `todowrite`.
+
+## TODOS
+
+```json
+{
+  "todos": [
+    {
+      "content": "Update useSettings to include sessionsPerPage",
+      "priority": "high",
+      "status": "pending"
+    },
+    {
+      "content": "Update SettingsPopover to allow changing sessionsPerPage",
+      "priority": "high",
+      "status": "pending"
+    },
+    {
+      "content": "Update StatsPage to persist sessionsPerPage in onSave",
+      "priority": "high",
+      "status": "pending"
+    },
+    {
+      "content": "Create Pagination component in frontend/src/components/stats/Pagination.tsx",
+      "priority": "high",
+      "status": "pending"
+    },
+    {
+      "content": "Update SessionList to implement client-side pagination logic and use Pagination component",
+      "priority": "high",
+      "status": "pending"
+    },
+    {
+      "content": "Write Playwright tests to verify pagination and take screenshots",
+      "priority": "medium",
+      "status": "pending"
+    }
+  ]
+}
+```
+
+## Current progress (git diff)
+
+```
+diff --git a/frontend/src/components/stats/SessionList.tsx b/frontend/src/components/stats/SessionList.tsx
+index 374e41c..2bd6ea7 100644
+--- a/frontend/src/components/stats/SessionList.tsx
++++ b/frontend/src/components/stats/SessionList.tsx
+@@ -1,15 +1,29 @@
+ import React, { useState } from 'react';
+ import { useSessions } from '../../hooks/useSleepSession';
++import { useSettings } from '../../hooks/useSettings';
++import { Pagination } from './Pagination';
+ import { Edit2, Check, X, Trash2 } from 'lucide-react';
+ import type { SleepSessionRead } from '../../types';
+ import { formatDateTime, toLocalDatetimeInputValue, getDurationMinutes, formatMinutes } from '../../utils/time';
+ 
+ export function SessionList() {
+   const { sessions, isLoading, updateSession, deleteSession, isDeleting } = useSessions();
++  const { settings } = useSettings();
++  const sessionsPerPage = settings.sessionsPerPage;
++
++  const [currentPage, setCurrentPage] = useState(1);
+   const [editingId, setEditingId] = useState<number | null>(null);
+   const [editStart, setEditStart] = useState<string>('');
+   const [editEnd, setEditEnd] = useState<string>('');
+ 
++  const totalPages = Math.ceil(sessions.length / sessionsPerPage);
++  const clampedPage = Math.max(1, Math.min(currentPage, totalPages || 1));
++
++  const paginatedSessions = sessions.slice(
++    (clampedPage - 1) * sessionsPerPage,
++    clampedPage * sessionsPerPage
++  );
++
+   if (isLoading) return <div className="text-center p-4">Loading sessions...</div>;
+   if (!sessions.length) return <div className="text-center p-4 text-gray-500">No sessions recorded.</div>;
+ 
+@@ -55,7 +69,7 @@ export function SessionList() {
+     <div className="bg-white p-4 rounded-xl shadow-sm border border-gray-200">
+       <h3 className="text-lg font-semibold mb-4 text-gray-800">Sleep Sessions</h3>
+       <div className="space-y-2">
+-        {sessions.map((s) => (
++        {paginatedSessions.map((s) => (
+           <div key={s.id} className="border-b border-gray-100 last:border-0 py-3 sm:py-2">
+             {editingId === s.id ? (
+               <div className="flex flex-col space-y-3 py-1">
+@@ -140,6 +154,13 @@ export function SessionList() {
+           </div>
+         ))}
+       </div>
++      {sessions.length > sessionsPerPage && (
++        <Pagination 
++          currentPage={clampedPage} 
++          totalPages={totalPages} 
++          onPageChange={setCurrentPage} 
++        />
++      )}
+     </div>
+   );
+ }
+diff --git a/frontend/src/components/stats/SettingsPopover.tsx b/frontend/src/components/stats/SettingsPopover.tsx
+index 005a302..8031392 100644
+--- a/frontend/src/components/stats/SettingsPopover.tsx
++++ b/frontend/src/components/stats/SettingsPopover.tsx
+@@ -6,15 +6,17 @@ interface SettingsPopoverProps {
+   dayEnd: string;
+   wakeupRef: string;
+   bedtimeRef: string;
+-  onSave: (settings: { dayStart: string; dayEnd: string; wakeupRef: string; bedtimeRef: string }) => void;
++  sessionsPerPage: number;
++  onSave: (settings: { dayStart: string; dayEnd: string; wakeupRef: string; bedtimeRef: string; sessionsPerPage: number }) => void;
+ }
+ 
+-export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSave }: SettingsPopoverProps) {
++export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, sessionsPerPage, onSave }: SettingsPopoverProps) {
+   const [isOpen, setIsOpen] = useState(false);
+   const [localDayStart, setLocalDayStart] = useState(dayStart);
+   const [localDayEnd, setLocalDayEnd] = useState(dayEnd);
+   const [localWakeupRef, setLocalWakeupRef] = useState(wakeupRef);
+   const [localBedtimeRef, setLocalBedtimeRef] = useState(bedtimeRef);
++  const [localSessionsPerPage, setLocalSessionsPerPage] = useState(sessionsPerPage);
+   const popoverRef = useRef<HTMLDivElement>(null);
+ 
+   useEffect(() => {
+@@ -22,7 +24,8 @@ export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSav
+     setLocalDayEnd(dayEnd);
+     setLocalWakeupRef(wakeupRef);
+     setLocalBedtimeRef(bedtimeRef);
+-  }, [dayStart, dayEnd, wakeupRef, bedtimeRef]);
++    setLocalSessionsPerPage(sessionsPerPage);
++  }, [dayStart, dayEnd, wakeupRef, bedtimeRef, sessionsPerPage]);
+ 
+   useEffect(() => {
+     const handleClickOutside = (e: MouseEvent) => {
+@@ -42,6 +45,7 @@ export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSav
+       dayEnd: localDayEnd,
+       wakeupRef: localWakeupRef,
+       bedtimeRef: localBedtimeRef,
++      sessionsPerPage: localSessionsPerPage,
+     });
+     setIsOpen(false);
+   };
+@@ -65,44 +69,58 @@ export function SettingsPopover({ dayStart, dayEnd, wakeupRef, bedtimeRef, onSav
+           
+           <div className="space-y-3">
+             <div>
+-<label htmlFor="day-start" className="block text-xs text-gray-500 mb-1">Day starts (HH:MM)</label>
+-<input
+-  id="day-start"
+-  type="time"
+-  value={localDayStart}
+-  onChange={(e) => setLocalDayStart(e.target.value)}
+-  className="w-full p-2 border rounded-md text-sm"
+-/>
++              <label htmlFor="day-start" className="block text-xs text-gray-500 mb-1">Day starts (HH:MM)</label>
++              <input
++                id="day-start"
++                type="time"
++                value={localDayStart}
++                onChange={(e) => setLocalDayStart(e.target.value)}
++                className="w-full p-2 border rounded-md text-sm"
++              />
+             </div>
+             <div>
+-<label htmlFor="day-end" className="block text-xs text-gray-500 mb-1">Day ends (HH:MM)</label>
+-<input
+-  id="day-end"
+-  type="time"
+-  value={localDayEnd}
+-  onChange={(e) => setLocalDayEnd(e.target.value)}
+-  className="w-full p-2 border rounded-md text-sm"
+-/>
++              <label htmlFor="day-end" className="block text-xs text-gray-500 mb-1">Day ends (HH:MM)</label>
++              <input
++                id="day-end"
++                type="time"
++                value={localDayEnd}
++                onChange={(e) => setLocalDayEnd(e.target.value)}
++                className="w-full p-2 border rounded-md text-sm"
++              />
+             </div>
+             <div>
+-<label htmlFor="wakeup-ref" className="block text-xs text-gray-500 mb-1">Wakeup ref (HH:MM)</label>
+-<input
+-  id="wakeup-ref"
+-  type="time"
+-  value={localWakeupRef}
+-  onChange={(e) => setLocalWakeupRef(e.target.value)}
+-  className="w-full p-2 border rounded-md text-sm"
+-/>
++              <label htmlFor="wakeup-ref" className="block text-xs text-gray-500 mb-1">Wakeup ref (HH:MM)</label>
++              <input
++                id="wakeup-ref"
++                type="time"
++                value={localWakeupRef}
++                onChange={(e) => setLocalWakeupRef(e.target.value)}
++                className="w-full p-2 border rounded-md text-sm"
++              />
+             </div>
+             <div>
+-<label htmlFor="bedtime-ref" className="block text-xs text-gray-500 mb-1">Bedtime ref (HH:MM)</label>
+-<input
+-  id="bedtime-ref"
+-  type="time"
+-  value={localBedtimeRef}
+-  onChange={(e) => setLocalBedtimeRef(e.target.value)}
+-  className="w-full p-2 border rounded-md text-sm"
+-/>
++              <label htmlFor="bedtime-ref" className="block text-xs text-gray-500 mb-1">Bedtime ref (HH:MM)</label>
++              <input
++                id="bedtime-ref"
++                type="time"
++                value={localBedtimeRef}
++                onChange={(e) => setLocalBedtimeRef(e.target.value)}
++                className="w-full p-2 border rounded-md text-sm"
++              />
++            </div>
++            <div>
++              <label htmlFor="sessions-per-page" className="block text-xs text-gray-500 mb-1">Results per page</label>
++              <select
++                id="sessions-per-page"
++                value={localSessionsPerPage}
++                onChange={(e) => setLocalSessionsPerPage(Number(e.target.value))}
++                className="w-full p-2 border rounded-md text-sm"
++              >
++                <option value={5}>5</option>
++                <option value={10}>10</option>
++                <option value={25}>25</option>
++                <option value={50}>50</option>
++              </select>
+             </div>
+           </div>
+ 
+diff --git a/frontend/src/components/stats/StatsPage.tsx b/frontend/src/components/stats/StatsPage.tsx
+index 2516d55..e3518c8 100644
+--- a/frontend/src/components/stats/StatsPage.tsx
++++ b/frontend/src/components/stats/StatsPage.tsx
+@@ -27,18 +27,20 @@ const StatsPage: React.FC = () => {
+           <h2 className="text-3xl font-extrabold text-slate-900 tracking-tight">Statistics</h2>
+           <p className="text-slate-500 text-sm mt-1">Overview of sleep patterns and trends</p>
+         </div>
+-        <SettingsPopover
+-          dayStart={settings.dayStart}
+-          dayEnd={settings.dayEnd}
+-          wakeupRef={settings.wakeupRef}
+-          bedtimeRef={settings.bedtimeRef}
+-          onSave={(s) => {
+-            update('dayStart', s.dayStart);
+-            update('dayEnd', s.dayEnd);
+-            update('wakeupRef', s.wakeupRef);
+-            update('bedtimeRef', s.bedtimeRef);
+-          }}
+-        />
++         <SettingsPopover
++           dayStart={settings.dayStart}
++           dayEnd={settings.dayEnd}
++           wakeupRef={settings.wakeupRef}
++           bedtimeRef={settings.bedtimeRef}
++           sessionsPerPage={settings.sessionsPerPage}
++           onSave={(s) => {
++             update('dayStart', s.dayStart);
++             update('dayEnd', s.dayEnd);
++             update('wakeupRef', s.wakeupRef);
++             update('bedtimeRef', s.bedtimeRef);
++             update('sessionsPerPage', s.sessionsPerPage);
++           }}
++         />
+       </div>
+ 
+       <div className="bg-white p-6 rounded-[2rem] shadow-md border border-gray-100">
+diff --git a/frontend/src/hooks/useSettings.ts b/frontend/src/hooks/useSettings.ts
+index c587fb3..d95899b 100644
+--- a/frontend/src/hooks/useSettings.ts
++++ b/frontend/src/hooks/useSettings.ts
+@@ -8,6 +8,7 @@ interface Settings {
+   wakeupRef: string;
+   bedtimeRef: string;
+   statsInterval: number;
++  sessionsPerPage: number;
+ }
+ 
+ const DEFAULT_SETTINGS: Settings = {
+@@ -16,6 +17,7 @@ const DEFAULT_SETTINGS: Settings = {
+   wakeupRef: '04:00',
+   bedtimeRef: '19:00',
+   statsInterval: 7,
++  sessionsPerPage: 10,
+ };
+ 
+ export function useSettings() {
+
+```
+
+## Last command
+
+The last command you ran was this:
+
+```
+npx playwright test frontend/tests/e2e/pagination.spec.ts --reporter=list
+```
+
+so please run this again and see the output, as this might help us know where to pick things up.