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>

apps/web/package.json

@@ -10,7 +10,8 @@
     "lint": "oxlint",
     "format": "oxfmt --config ../../.oxfmtrc.json",
     "format:check": "oxfmt --check --config ../../.oxfmtrc.json",
-    "check-types": "tsc --noEmit"
+    "check-types": "tsc --noEmit",
+    "test": "vitest run"
   },
   "dependencies": {
     "@base-ui/react": "1.3.0",
@@ -28,7 +29,7 @@
     "@tabler/icons-react": "3.40.0",
     "@tanstack/react-hotkeys": "0.4.2",
     "@tanstack/react-query": "catalog:",
-    "@tanstack/react-router": "1.168.1",
+    "@tanstack/react-router": "1.168.2",
     "better-auth": "catalog:",
     "class-variance-authority": "0.7.1",
     "clsx": "2.1.1",
@@ -51,16 +52,19 @@
     "@tanstack/devtools-vite": "0.6.0",
     "@tanstack/react-devtools": "0.10.0",
     "@tanstack/react-query-devtools": "5.94.5",
-    "@tanstack/react-router-devtools": "1.166.10",
-    "@tanstack/router-plugin": "1.167.2",
+    "@tanstack/react-router-devtools": "1.166.11",
+    "@tanstack/router-plugin": "1.167.3",
     "@types/bun": "catalog:",
     "@types/node": "catalog:",
     "@types/react": "catalog:",
     "@types/react-dom": "19.2.3",
     "@vitejs/plugin-react": "6.0.1",
+    "@vitest/browser": "catalog:",
+    "@vitest/browser-playwright": "catalog:",
     "babel-plugin-react-compiler": "1.0.0",
     "tailwindcss": "catalog:",
     "typescript": "catalog:",
-    "vite": "8.0.1"
+    "vite": "8.0.1",
+    "vitest": "catalog:"
   }
 }

apps/web/src/lib/theme.test.ts

@@ -1,4 +1,4 @@
-import { describe, expect, test } from "bun:test";
+import { describe, expect, test } from "vitest";
 
 import { getThemeCssProperties, hexToRelativeLuminance } from "./theme";
 

apps/web/vitest.config.ts

@@ -0,0 +1,13 @@
+import { playwright } from "@vitest/browser-playwright";
+import { defineProject } from "vitest/config";
+
+export default defineProject({
+  test: {
+    include: ["src/**/*.test.{ts,tsx}"],
+    browser: {
+      enabled: true,
+      provider: playwright(),
+      instances: [{ browser: "chromium", headless: true }],
+    },
+  },
+});