feat(gitea): add Gitea/Forgejo as a git provider

Full parity with the existing GitLab provider:
- Server module packages/web/server/lib/gitea (auth/client/repo/routes + docs + tests)
  with Gitea REST v1 API, PAT + base URL auth, multi-account storage
- Shared GiteaAPI types and web API client
- Provider detection generalized with user-configurable custom domains
  per provider (github/gitlab/gitea), additive with built-in defaults
  (github.com, gitlab.com) and connected-account hosts; precedence
  github -> gitlab -> gitea
- Gitea PR view, issues section, pickers, integration dialog, branch
  PR status helper, settings UI (PAT + base URL + custom domains)
- Magic prompts (gitea.pr.review, gitea.issue.review) and full 11-locale
  i18n parity

packages/web/server/lib/gitea/index.js

@@ -0,0 +1,21 @@
+export {
+  getGiteaAuth,
+  getGiteaAuthAccounts,
+  setGiteaAuth,
+  activateGiteaAuth,
+  clearGiteaAuth,
+  normalizeBaseUrl,
+  GITEA_AUTH_FILE,
+} from './auth.js';
+
+export {
+  createGiteaClient,
+  getGiteaClientOrNull,
+  isGiteaRateLimited,
+  noteGiteaRateLimit,
+} from './client.js';
+
+export {
+  parseGiteaRemoteUrl,
+  resolveGiteaRepoFromDirectory,
+} from './repo.js';