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/hooks/use-encounter.ts

@@ -37,14 +37,7 @@ import {
 	resolveCreatureName,
 } from "@initiative/domain";
 import { useCallback, useEffect, useReducer, useRef } from "react";
-import {
-	loadEncounter,
-	saveEncounter,
-} from "../persistence/encounter-storage.js";
-import {
-	loadUndoRedoStacks,
-	saveUndoRedoStacks,
-} from "../persistence/undo-redo-storage.js";
+import { useAdapters } from "../contexts/adapter-context.js";
 
 // -- Types --
 
@@ -111,11 +104,14 @@ function deriveNextId(encounter: Encounter): number {
 	return max;
 }
 
-function initializeState(): EncounterState {
-	const encounter = loadEncounter() ?? EMPTY_ENCOUNTER;
+function initializeState(
+	loadEncounterFn: () => Encounter | null,
+	loadUndoRedoFn: () => UndoRedoState,
+): EncounterState {
+	const encounter = loadEncounterFn() ?? EMPTY_ENCOUNTER;
 	return {
 		encounter,
-		undoRedoState: loadUndoRedoStacks(),
+		undoRedoState: loadUndoRedoFn(),
 		events: [],
 		nextId: deriveNextId(encounter),
 		lastCreatureId: null,
@@ -385,7 +381,10 @@ function dispatchEncounterAction(
 // -- Hook --
 
 export function useEncounter() {
-	const [state, dispatch] = useReducer(encounterReducer, null, initializeState);
+	const { encounterPersistence, undoRedoPersistence } = useAdapters();
+	const [state, dispatch] = useReducer(encounterReducer, null, () =>
+		initializeState(encounterPersistence.load, undoRedoPersistence.load),
+	);
 	const { encounter, undoRedoState, events } = state;
 
 	const encounterRef = useRef(encounter);
@@ -394,12 +393,12 @@ export function useEncounter() {
 	undoRedoRef.current = undoRedoState;
 
 	useEffect(() => {
-		saveEncounter(encounter);
-	}, [encounter]);
+		encounterPersistence.save(encounter);
+	}, [encounter, encounterPersistence]);
 
 	useEffect(() => {
-		saveUndoRedoStacks(undoRedoState);
-	}, [undoRedoState]);
+		undoRedoPersistence.save(undoRedoState);
+	}, [undoRedoState, undoRedoPersistence]);
 
 	// Escape hatches for useInitiativeRolls (needs raw port access)
 	const makeStore = useCallback((): EncounterStore => {