feat: migrate test runner from Bun to Vitest

- Replace bun:test with Vitest across all 22 test files
- Create @sofa/test package with shared setup and DB test helpers
  - setup.ts: vi.mock for @sofa/db/client, Bun.randomUUIDv7 polyfill
  - db.ts: in-memory SQLite via better-sqlite3, seed helpers
- Add per-project vitest configs (packages/core, apps/web)
- Add root vitest.config.ts with projects and v8 coverage
- Set up @vitest/browser + Playwright for web component tests
- Move validateBackupDatabase from core/backup.ts to @sofa/db/client
- Derive required backup tables from schema instead of hard-coded list
- Update CI workflow with Playwright install and Codecov upload
- Update CLAUDE.md documentation for Vitest

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

package.json

@@ -7,15 +7,7 @@
       "packages/*"
     ],
     "catalog": {
-      "@better-auth/expo": "1.5.5",
-      "@orpc/client": "1.13.9",
-      "@orpc/contract": "1.13.9",
-      "@orpc/tanstack-query": "1.13.9",
-      "@tanstack/react-query": "5.94.5",
-      "@types/bun": "1.3.11",
-      "@types/node": "25.5.0",
-      "@types/react": "19.2.14",
-      "better-auth": "1.5.5",
+      "@better-auth/expo": "1.5.6",
       "@lingui/babel-plugin-lingui-macro": "5.9.3",
       "@lingui/cli": "5.9.3",
       "@lingui/conf": "5.9.3",
@@ -24,12 +16,26 @@
       "@lingui/metro-transformer": "5.9.3",
       "@lingui/react": "5.9.3",
       "@lingui/vite-plugin": "5.9.3",
+      "@orpc/client": "1.13.9",
+      "@orpc/contract": "1.13.9",
+      "@orpc/tanstack-query": "1.13.9",
+      "@tanstack/react-query": "5.94.5",
+      "@types/bun": "1.3.11",
+      "@types/node": "25.5.0",
+      "@types/react": "19.2.14",
+      "@vitest/browser": "4.1.0",
+      "@vitest/browser-playwright": "4.1.0",
+      "@vitest/coverage-v8": "4.1.0",
+      "better-auth": "1.5.6",
+      "drizzle-kit": "1.0.0-beta.18-7eb39f0",
+      "drizzle-orm": "1.0.0-beta.18-7eb39f0",
       "react": "19.2.0",
       "react-dom": "19.2.0",
       "tailwind-merge": "3.5.0",
       "tailwindcss": "4.2.2",
       "thumbhash": "0.1.1",
       "typescript": "5.9.3",
+      "vitest": "4.1.0",
       "zod": "4.3.6"
     }
   },
@@ -53,11 +59,16 @@
     "@lingui/cli": "catalog:",
     "@lingui/conf": "catalog:",
     "@lingui/format-po": "catalog:",
+    "@vitest/browser": "catalog:",
+    "@vitest/browser-playwright": "catalog:",
+    "@vitest/coverage-v8": "catalog:",
     "eslint-plugin-lingui": "0.11.0",
     "oxfmt": "0.41.0",
     "oxlint": "1.56.0",
+    "playwright": "1.58.2",
     "turbo": "2.8.20",
-    "typescript": "catalog:"
+    "typescript": "catalog:",
+    "vitest": "catalog:"
   },
   "packageManager": "bun@1.3.11"
 }