Separate user intent from planner output via day assertions

The calendar mixed two kinds of truth in one table. `planned_leave_day` was
simultaneously the allocator's output cache, the user's override store
(`is_pinned`, plus ad-hoc rows with no `wish_id`), and the resource ledger that
analytics and the age-4 maths read. The planner therefore had to ask "am I
allowed to touch this row?" on every sync, and got it wrong at the edges.

Every user assertion is now one `day_assertion` row — a concrete `day_type`
replaces a pinned day, a row with no `wish_id` replaces an ad-hoc day, and
`day_type='none'` replaces `planned_day_exclusion`. `planned_leave_day` becomes
purely derived with a single writer, and `PlanningService.pinned_keys()` is the
single answer to "is this day pinned", used by the allocator's loader, by
`sync_plan` and by the read router alike.

On top of that, every calendar band is now a real event: an ad-hoc band opens
the same full editor as a wish-backed one and saving it promotes it to a
`LeaveWish`, so it can be named, repeated yearly, assigned to either or both
parents, and handed to the planner. "Planering" is a `moveable` toggle plus a
from/to month bound plus a separate lock/unlock action on the days themselves,
replacing a three-rung ladder whose "planner decides" rung set a search window
equal to the drawn dates and so could never move anything.

Bugs found and fixed along the way:

- The plan erased its own history. Fixed windows clip to today, so an elapsed
  auto-placed day fell into `stale_keys` and was deleted on the next sync —
  and a background sync runs on every workspace load. Past rows are now frozen
  and counted as spent.
- Migration 010's downgrade silently destroyed every pinned day and exclusion
  (`is_pinned` returned as DEFAULT 0, the exclusion table came back empty,
  exit 0, no warning). It now reconstructs both from `day_assertion`, and 009
  itemises what it cannot recover before dropping the table.
- Deleting a period left its assertions behind, locking those dates forever
  with no UI path to clear them. Wish deletion now clears them by `wish_id`.
- `DayAssertionService` and `LeaveWishService` committed multi-statement writes
  without a transaction; a crash mid-write diverged the tables or half-deleted
  a series. Both now run in a unit of work.
- A sibling year's shortfall was never surfaced: the toast only inspected the
  edited occurrence's outcome, so a fully unfunded later year rendered as an
  empty band with no warning.
- A flexible window whose bound had entirely elapsed was dropped from the
  proposal with no outcome at all. It now reports as `unplaced`.
- Unlocking a period deleted its days instead of returning them to the planner.
- The e2e global setup posted to a route deleted in this change, which would
  have failed the whole suite before its first test.

Gates: backend 938 tests / 91% coverage, frontend 1351 / 97.4 | 92.2 | 94.37 |
97.4. Migrations 009 and 010 audited against a hand-built realistic database:
the upgrade reconciles exactly and a constraint violation fails safe, leaving
the schema at 008.

Not complete. Step 4's toggle, month picker and lock/unlock action are verified
by browser walk and unit tests, but the partial-lock readout was not exercised.
`ideas.md` §7 adds a full plan for the vacation-forfeiture defect (the planner
detects expiring days and then does nothing about them) — not implemented here.
Remaining smaller items are listed in the session's restructure notes.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T4wjgbVL4HAC5Rdaw75VbV

frontend/tests/fixtures/hooks.ts

@@ -19,7 +19,7 @@ import type { usePlannedDays } from '@/hooks/usePlannedDays'
 import type { useScraperFetch } from '@/hooks/useScraperFetch'
 import type { useWorkspaceMembers } from '@/hooks/useWorkspaceMembers'
 import type { useOptimizationTips } from '@/hooks/useOptimizationTips'
-import type { usePlannedDayExclusions } from '@/hooks/usePlannedDayExclusions'
+import type { useDayAssertions } from '@/hooks/useDayAssertions'
 import type { useDayOverrides } from '@/hooks/useDayOverrides'
 import type { useLeaveWishes } from '@/hooks/useLeaveWishes'
 import type { usePlanProposal } from '@/hooks/usePlanProposal'
@@ -68,8 +68,6 @@ export function makePlanSyncContextValue(
   overrides: Partial<ReturnType<typeof usePlanSyncContext>> = {},
 ): ReturnType<typeof usePlanSyncContext> {
   return {
-    pendingEvictionPreview: null,
-    clearPendingEvictionPreview: vi.fn(),
     latestProposal: null,
     latestProposalVersion: 0,
     ...overrides,
@@ -126,9 +124,6 @@ export function makePlannedDaysResult(
     isLoading: false,
     error: null,
     refresh: vi.fn(),
-    add: vi.fn(),
-    update: vi.fn(),
-    remove: vi.fn(),
     ...overrides,
   }
 }
@@ -190,15 +185,15 @@ export function makeDayOverridesResult(
   }
 }
 
-export function makePlannedDayExclusionsResult(
-  overrides: Partial<ReturnType<typeof usePlannedDayExclusions>> = {},
-): ReturnType<typeof usePlannedDayExclusions> {
+export function makeDayAssertionsResult(
+  overrides: Partial<ReturnType<typeof useDayAssertions>> = {},
+): ReturnType<typeof useDayAssertions> {
   return {
     data: [],
     isLoading: false,
     error: null,
-    exclude: vi.fn(),
-    restore: vi.fn(),
+    assertDay: vi.fn(),
+    clear: vi.fn(),
     ...overrides,
   }
 }
@@ -239,6 +234,7 @@ export function makePlanSyncResult(
     error: null,
     lastChanges: null,
     sync: vi.fn(),
+    syncWithWish: vi.fn(),
     ...overrides,
   }
 }