Introduce adapter injection and migrate test suite

Replace direct adapter/persistence imports with context-based injection
(AdapterContext + useAdapters) so tests use in-memory implementations
instead of vi.mock. Migrate component tests from context mocking to
AllProviders with real hooks. Extract export/import logic from ActionBar
into useEncounterExportImport hook. Add bestiary-cache and
bestiary-index-adapter test suites. Raise adapter coverage thresholds
(68→80 lines, 56→62 branches).

77 test files, 891 tests, all passing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/src/adapters/production-adapters.ts

@@ -0,0 +1,44 @@
+import type { Adapters } from "../contexts/adapter-context.js";
+import {
+	loadEncounter,
+	saveEncounter,
+} from "../persistence/encounter-storage.js";
+import {
+	loadPlayerCharacters,
+	savePlayerCharacters,
+} from "../persistence/player-character-storage.js";
+import {
+	loadUndoRedoStacks,
+	saveUndoRedoStacks,
+} from "../persistence/undo-redo-storage.js";
+import * as bestiaryCache from "./bestiary-cache.js";
+import * as bestiaryIndex from "./bestiary-index-adapter.js";
+
+export const productionAdapters: Adapters = {
+	encounterPersistence: {
+		load: loadEncounter,
+		save: saveEncounter,
+	},
+	undoRedoPersistence: {
+		load: loadUndoRedoStacks,
+		save: saveUndoRedoStacks,
+	},
+	playerCharacterPersistence: {
+		load: loadPlayerCharacters,
+		save: savePlayerCharacters,
+	},
+	bestiaryCache: {
+		cacheSource: bestiaryCache.cacheSource,
+		isSourceCached: bestiaryCache.isSourceCached,
+		getCachedSources: bestiaryCache.getCachedSources,
+		clearSource: bestiaryCache.clearSource,
+		clearAll: bestiaryCache.clearAll,
+		loadAllCachedCreatures: bestiaryCache.loadAllCachedCreatures,
+	},
+	bestiaryIndex: {
+		loadIndex: bestiaryIndex.loadBestiaryIndex,
+		getAllSourceCodes: bestiaryIndex.getAllSourceCodes,
+		getDefaultFetchUrl: bestiaryIndex.getDefaultFetchUrl,
+		getSourceDisplayName: bestiaryIndex.getSourceDisplayName,
+	},
+};