Server overhaul: clear clippy::pedantic wins

Taken from a -W clippy::pedantic scan, no allow added: map_or/map_or_else, method references instead of closures,
clone_from, write! instead of push_str(format!), borrowed Option<&str>, push_of without a needless Option, the
envelope's entity moved instead of cloned, the scheduler's plan() no longer a needless async fn (its doc now says
what it does on failure), sort_unstable, digit separators and inline format args in tests. Not taken: missing
# Errors/# Panics docs, must_use, doc backticks, assert!(x.is_empty()) in tests, too_many_lines.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TQd3pEP9UeN2uifbHknQ7B

server/crates/kvitt-server/tests/core_api/generation.rs

@@ -301,7 +301,14 @@ async fn an_existing_period_is_skipped_silently_by_the_unique_index() {
     let (id, _) = new_template(&app, json!({"day_of_month": 1, "start_period": "2026-11"})).await;
     // Another writer already created 2026-11 (as a racing scheduler run would).
     let other = app
-        .insert_expense(ACCOUNT_1, HOME, 1250000, ADMIN_ID, (750000, 500000), false)
+        .insert_expense(
+            ACCOUNT_1,
+            HOME,
+            1_250_000,
+            ADMIN_ID,
+            (750_000, 500_000),
+            false,
+        )
         .await;
     sqlx::query(
         "UPDATE expenses SET recurring_template_id = ?, recurring_period = '2026-11' WHERE id = ?",
@@ -469,7 +476,10 @@ async fn archived_account_continues_and_edits_affect_only_later_expenses() {
         dates(&generated(&app, id).await),
         ["2026-10-01", "2026-11-01"]
     );
-    assert_eq!(expense_of(&app, id, "2026-10").await["amount_ore"], 1250000);
+    assert_eq!(
+        expense_of(&app, id, "2026-10").await["amount_ore"],
+        1_250_000
+    );
     let november = expense_of(&app, id, "2026-11").await;
     assert_eq!(november["amount_ore"], 2000);
     assert_eq!(november["account_id"], ACCOUNT_1);

server/crates/kvitt-server/tests/core_api/logging.rs

@@ -81,7 +81,7 @@ async fn logs_hold_no_personal_content() {
             "/recurring-templates",
             &admin_token(),
             Some(template_body(json!({
-                "description": "Hemligbeskrivning", "notes": "Hemliganteckning", "amount_ore": 987654,
+                "description": "Hemligbeskrivning", "notes": "Hemliganteckning", "amount_ore": 987_654,
                 "day_of_month": 1, "start_period": "2026-09"
             }))),
         )

server/crates/kvitt-server/tests/core_api/rate_limit.rs

@@ -80,7 +80,7 @@ async fn unknown_tokens_count_against_the_ip_but_known_devices_keep_working() {
         200
     );
     for i in 0..60 {
-        let tok = format!("kvt_{:0>43}", i);
+        let tok = format!("kvt_{i:0>43}");
         let reply = app.send(from("192.0.2.1:1", None, "/me", Some(&tok))).await;
         assert_error(&reply, 401, "unauthorized");
     }

server/crates/kvitt-server/tests/openapi_contract.rs

@@ -206,7 +206,7 @@ fn canon(value: &Value, names: bool) -> Value {
                             Some(Value::Array(inner))
                                 if alternative.as_object().is_some_and(|o| o.len() == 1) =>
                             {
-                                flat.extend(inner.iter().cloned())
+                                flat.extend(inner.iter().cloned());
                             }
                             _ => flat.push(alternative),
                         }
@@ -383,7 +383,7 @@ fn generated_document_equals_contract() {
             paths
                 .values()
                 .filter_map(Value::as_object)
-                .map(|m| m.len())
+                .map(serde_json::Map::len)
                 .sum::<usize>()
         })
         .unwrap_or(0);

server/crates/kvitt-server/tests/skeleton/wire_examples.rs

@@ -104,7 +104,6 @@ fn every_example_round_trips() {
                 checked += 1;
             } else if dir_name == "push" {
                 // FCM payloads (SPEC §14.6) are built by the push sender, not by a wire type of this crate.
-                continue;
             } else if check(&name, &example) {
                 checked += 1;
             } else {

server/crates/kvitt-server/tests/sync_api/audit.rs

@@ -44,7 +44,7 @@ async fn generation_writes_recurring_audit_with_server_now_and_no_device() {
     assert_eq!((a.client_at.as_str(), a.server_at.as_str()), (NOW, NOW));
     assert_eq!(
         a.changes[3],
-        json!({"field": "amount_ore", "old": null, "new": 1250000})
+        json!({"field": "amount_ore", "old": null, "new": 1_250_000})
     );
     // The entry reaches the phones through pull.
     let page = pull(&app, &admin_token(), 0, None).await.json;

server/crates/kvitt-server/tests/sync_api/pull.rs

@@ -28,7 +28,7 @@ fn versions(page: &Value) -> Vec<i64> {
                 .map(|r| r["server_version"].as_i64().unwrap())
         })
         .collect();
-    all.sort();
+    all.sort_unstable();
     all
 }
 
@@ -99,7 +99,7 @@ async fn the_first_page_has_everything_in_version_order_with_the_epoch_and_serve
             .map(|r| r["server_version"].as_i64().unwrap())
             .collect();
         let mut sorted = v.clone();
-        sorted.sort();
+        sorted.sort_unstable();
         assert_eq!(v, sorted, "{a} sorted by server_version");
     }
     // Children come with the parent.