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/repo.js

@@ -0,0 +1,124 @@
+import { getRemoteUrl } from '../git/index.js';
+import { getGiteaAuthAccounts, normalizeBaseUrl } from './auth.js';
+
+// When no explicit host allowlist is provided, accept any host that matches the
+// base URL of a stored Gitea account. Gitea/Forgejo is self-hosted, so there is
+// no default host. Never github.com or gitlab.com — those belong to other
+// providers and must not be classified as Gitea.
+function acceptedHosts(knownHosts) {
+  const hosts = new Set();
+  if (knownHosts instanceof Set) {
+    for (const host of knownHosts) {
+      if (typeof host === 'string' && host.trim()) {
+        hosts.add(host.trim().toLowerCase());
+      }
+    }
+    return hosts;
+  }
+  if (Array.isArray(knownHosts)) {
+    for (const host of knownHosts) {
+      if (typeof host === 'string' && host.trim()) {
+        hosts.add(host.trim().toLowerCase());
+      }
+    }
+    return hosts;
+  }
+
+  for (const account of getGiteaAuthAccounts()) {
+    try {
+      const host = new URL(normalizeBaseUrl(account.baseUrl) || account.baseUrl).hostname.toLowerCase();
+      if (host) {
+        hosts.add(host);
+      }
+    } catch {
+      // ignore malformed stored account base URLs
+    }
+  }
+  return hosts;
+}
+
+/**
+ * Parse a Gitea/Forgejo remote URL into `{ owner, repo, host, baseUrl, url }`.
+ *
+ * Gitea repos are flat `owner/repo` (no multi-segment namespaces). Supports:
+ * - `git@HOST:owner/repo.git`
+ * - `ssh://git@HOST/owner/repo.git`
+ * - `https://HOST/owner/repo(.git)`
+ *
+ * `knownHosts` (optional Set of hostnames) restricts which hosts are accepted.
+ * When omitted, hosts from stored auth accounts are accepted. `github.com` and
+ * `gitlab.com` are never accepted.
+ */
+export const parseGiteaRemoteUrl = (raw, knownHosts) => {
+  if (typeof raw !== 'string') {
+    return null;
+  }
+  const value = raw.trim();
+  if (!value) {
+    return null;
+  }
+
+  let host = '';
+  let path = '';
+
+  // git@HOST:owner/repo.git
+  const scpLike = value.match(/^git@([^:]+):(.+)$/);
+  if (scpLike) {
+    host = scpLike[1].toLowerCase();
+    path = scpLike[2];
+  } else if (value.startsWith('ssh://') || /^https?:\/\//.test(value)) {
+    try {
+      const url = new URL(value);
+      host = url.hostname.toLowerCase();
+      path = url.pathname.replace(/^\/+/, '');
+    } catch {
+      return null;
+    }
+  } else {
+    return null;
+  }
+
+  if (!host) {
+    return null;
+  }
+  if (host === 'github.com' || host === 'gitlab.com') {
+    return null;
+  }
+  if (!acceptedHosts(knownHosts).has(host)) {
+    return null;
+  }
+
+  path = path.replace(/\/+$/, '');
+  if (path.endsWith('.git')) {
+    path = path.slice(0, -4);
+  }
+  const segments = path.split('/').filter(Boolean);
+  // Gitea repos are flat owner/repo — exactly two segments.
+  if (segments.length !== 2) {
+    return null;
+  }
+  const owner = segments[0];
+  const repo = segments[1];
+  if (!owner || !repo) {
+    return null;
+  }
+
+  return {
+    owner,
+    repo,
+    host,
+    baseUrl: `https://${host}`,
+    url: `https://${host}/${owner}/${repo}`,
+  };
+};
+
+export async function resolveGiteaRepoFromDirectory(directory, remoteName = 'origin') {
+  const remoteUrl = await getRemoteUrl(directory, remoteName).catch(() => null);
+  if (!remoteUrl) {
+    return { repo: null, remoteUrl: null };
+  }
+  return {
+    repo: parseGiteaRemoteUrl(remoteUrl),
+    remoteUrl,
+  };
+}