Make Cobble a local install: setup flow, bots-first admin, settings

Local, password-only auth:
- No public pages; everything outside /admin and /auth redirects in
- First run (no users) sends every page to /auth/signup, which creates
  the super admin (user #1) once and then locks
- Login is email/username + password; removed the emailed-code flow,
  /auth/sso and email password reset
- Google login kept for existing accounts only, never creates them
- seed-super-admin now requires SEED_SUPER_ADMIN_PASSWORD

Bots-first admin:
- /admin and closed sections (people, logs, backups) redirect to
  /admin/bots; only bots and settings are live (AdminSections)
- Removed the old admin layout; every /admin page uses the bots rail
- Coordinator bot created at signup/seed and by /admin/bots
  (ensureCoordinatorBot), which redirects to its chat
- bots.system_prompt (markdown) with a default coordinator prompt
- seed-bots reuses the existing coordinator

Settings:
- Sub pages general (default), profile, change-password, listed in the
  rail with a back link; unknown settings paths redirect to general
- Redesigned settings UI: pane header, grouped rows, sticky save bar
- General: System/Light/Dark theme, saved per device

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/layouts/bots/(dict)/rail-user-menu-dict.ts

@@ -6,6 +6,7 @@ import {
     SlidersHorizontal,
     type LucideIcon,
 } from "lucide-react";
+import { SettingsDefaultPath } from "@/src/dict/settings-pages-dict";
 
 export type RailUserMenuItem = {
     title: string;
@@ -26,9 +27,9 @@ export type RailUserMenuItem = {
  * destinations are only reachable from here.
  */
 export const RailUserMenuItems: RailUserMenuItem[] = [
-    { title: "Activity", url: "/admin/logs", Icon: Activity },
+    { title: "Activity", Icon: Activity },
     { title: "Routines", Icon: Clock },
-    { title: "Settings", url: "/admin/settings", Icon: SlidersHorizontal },
+    { title: "Settings", url: SettingsDefaultPath, Icon: SlidersHorizontal },
     { title: "Help", Icon: CircleHelp },
     { title: "Sign out", url: "/auth/logout", Icon: LogOut, destructive: true },
 ];