feat: in-app support form with email + Gitea issue integration (v0.49.0)

Users can now report bugs, suggestions, or questions from a new /support
page. Each submission sends a confirmation email and, when GITEA_URL/
GITEA_TOKEN/GITEA_REPO are configured in admin Settings, opens a labeled
issue on that repo automatically (best-effort — failure doesn't block the
ticket). Admins get a Support section to triage status and retry failed
Gitea issue creation.

New support_tickets table, gitea.ts client, site-settings entries for the
three new secrets, and OpenAPI docs for the two user-facing endpoints.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/lib/site-settings.ts

@@ -15,13 +15,17 @@ export type SiteSettingKey =
   | "DEFAULT_VISION_PROVIDER"
   | "DEFAULT_VISION_MODEL"
   | "DEFAULT_MEAL_PLAN_PROVIDER"
-  | "DEFAULT_MEAL_PLAN_MODEL";
+  | "DEFAULT_MEAL_PLAN_MODEL"
+  | "GITEA_URL"
+  | "GITEA_TOKEN"
+  | "GITEA_REPO";
 
 const SECRET_KEYS: SiteSettingKey[] = [
   "OPENAI_API_KEY",
   "ANTHROPIC_API_KEY",
   "OPENROUTER_API_KEY",
   "VAPID_PRIVATE_KEY",
+  "GITEA_TOKEN",
 ];
 
 export function isSecretKey(key: SiteSettingKey): boolean {
@@ -58,6 +62,9 @@ export async function getAllSiteSettings(): Promise<Record<string, { value: stri
     "DEFAULT_VISION_MODEL",
     "DEFAULT_MEAL_PLAN_PROVIDER",
     "DEFAULT_MEAL_PLAN_MODEL",
+    "GITEA_URL",
+    "GITEA_TOKEN",
+    "GITEA_REPO",
   ];
 
   const result: Record<string, { value: string | null; isSecret: boolean; fromDb: boolean }> = {};