Add E2E testing (#201)

* feat: add E2E testing infrastructure with fake GitHub, Playwright, and CI workflow

- Add fake GitHub API server (tests/e2e/fake-github-server.ts) with
  management API for seeding test data
- Add Playwright E2E test suite covering full mirror workflow:
  service health checks, user registration, config, sync, verify
- Add Docker Compose for E2E Gitea instance
- Add orchestrator script (run-e2e.sh) with cleanup
- Add GitHub Actions workflow (e2e-tests.yml) with Gitea service container
- Make GITHUB_API_URL configurable via env var for testing
- Add npm scripts: test:e2e, test:e2e:ci, test:e2e:keep, test:e2e:cleanup

* feat: add real git repos + backup config testing to E2E suite

- Create programmatic test git repos (create-test-repos.ts) with real
  commits, branches (main, develop, feature/*), and tags (v1.0.0, v1.1.0)
- Add git-server container to docker-compose serving bare repos via
  dumb HTTP protocol so Gitea can actually clone them
- Update fake GitHub server to emit reachable clone_url fields pointing
  to the git-server container (configurable via GIT_SERVER_URL env var)
- Add management endpoint POST /___mgmt/set-clone-url for runtime config
- Update E2E spec with real mirroring verification:
  * Verify repos appear in Gitea with actual content
  * Check branches, tags, commits, file content
  * Verify 4/4 repos mirrored successfully
- Add backup configuration test suite:
  * Enable/disable backupBeforeSync config
  * Toggle blockSyncOnBackupFailure
  * Trigger re-sync with backup enabled and verify activities
  * Verify config persistence across changes
- Update CI workflow to use docker compose (not service containers)
  matching the local run-e2e.sh approach
- Update cleanup.sh for git-repos directory and git-server port
- All 22 tests passing with real git content verification

* refactor: split E2E tests into focused files + add force-push tests

Split the monolithic e2e.spec.ts (1335 lines) into 5 focused spec files
and a shared helpers module:

  helpers.ts                 — constants, GiteaAPI, auth, saveConfig, utilities
  01-health.spec.ts          — service health checks (4 tests)
  02-mirror-workflow.spec.ts — full first-mirror journey (8 tests)
  03-backup.spec.ts          — backup config toggling (6 tests)
  04-force-push.spec.ts      — force-push simulation & backup verification (9 tests)
  05-sync-verification.spec.ts — dynamic repos, content integrity, reset (5 tests)

The force-push tests are the critical addition:
  F0: Record original state (commit SHAs, file content)
  F1: Rewrite source repo history (simulate force-push)
  F2: Sync to Gitea WITHOUT backup
  F3: Verify data loss — LICENSE file gone, README overwritten
  F4: Restore source, re-mirror to clean state
  F5: Enable backup, force-push again, sync through app
  F6: Verify Gitea reflects the force-push
  F7: Verify backup system was invoked (snapshot activities logged)
  F8: Restore source repo for subsequent tests

Also added to helpers.ts:
  - GiteaAPI.getBranch(), .getCommit(), .triggerMirrorSync()
  - getRepositoryIds(), triggerMirrorJobs(), triggerSyncRepo()

All 32 tests passing.

* Try to fix actions

* Try to fix the other action

* Add debug info to check why e2e action is failing

* More debug info

* Even more debug info

* E2E fix attempt #1

* E2E fix attempt #2

* more debug again

* E2E fix attempt #3

* E2E fix attempt #4

* Remove a bunch of debug info

* Hopefully fix backup bug

* Force backups to succeed

package.json

@@ -36,6 +36,10 @@
     "test": "bun test",
     "test:watch": "bun test --watch",
     "test:coverage": "bun test --coverage",
+    "test:e2e": "bash tests/e2e/run-e2e.sh",
+    "test:e2e:ci": "bash tests/e2e/run-e2e.sh --ci",
+    "test:e2e:keep": "bash tests/e2e/run-e2e.sh --keep",
+    "test:e2e:cleanup": "bash tests/e2e/cleanup.sh",
     "astro": "bunx --bun astro"
   },
   "overrides": {
@@ -73,7 +77,7 @@
     "@types/canvas-confetti": "^1.9.0",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
-    "astro": "^5.17.3",
+    "astro": "^5.18.0",
     "bcryptjs": "^3.0.3",
     "better-auth": "1.4.19",
     "buffer": "^6.0.3",
@@ -101,11 +105,13 @@
     "zod": "^4.3.6"
   },
   "devDependencies": {
+    "@playwright/test": "^1.58.2",
     "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^16.3.2",
     "@types/bcryptjs": "^3.0.0",
     "@types/bun": "^1.3.9",
     "@types/jsonwebtoken": "^9.0.10",
+    "@types/node": "^25.3.2",
     "@types/uuid": "^11.0.0",
     "@vitejs/plugin-react": "^5.1.4",
     "drizzle-kit": "^0.31.9",