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/components/bulk-import-prompt.tsx

@@ -1,6 +1,6 @@
 import { Loader2 } from "lucide-react";
 import { useId, useState } from "react";
-import { getAllSourceCodes } from "../adapters/bestiary-index-adapter.js";
+import { useAdapters } from "../contexts/adapter-context.js";
 import { useBestiaryContext } from "../contexts/bestiary-context.js";
 import { useBulkImportContext } from "../contexts/bulk-import-context.js";
 import { useSidePanelContext } from "../contexts/side-panel-context.js";
@@ -11,6 +11,7 @@ const DEFAULT_BASE_URL =
 	"https://raw.githubusercontent.com/5etools-mirror-3/5etools-src/main/data/bestiary/";
 
 export function BulkImportPrompt() {
+	const { bestiaryIndex } = useAdapters();
 	const { fetchAndCacheSource, isSourceCached, refreshCache } =
 		useBestiaryContext();
 	const { state: importState, startImport, reset } = useBulkImportContext();
@@ -18,7 +19,7 @@ export function BulkImportPrompt() {
 
 	const [baseUrl, setBaseUrl] = useState(DEFAULT_BASE_URL);
 	const baseUrlId = useId();
-	const totalSources = getAllSourceCodes().length;
+	const totalSources = bestiaryIndex.getAllSourceCodes().length;
 
 	const handleStart = (url: string) => {
 		startImport(url, fetchAndCacheSource, isSourceCached, refreshCache);