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/dict/admin-sections-dict.ts

@@ -0,0 +1,8 @@
+/**
+ * The admin sections that are live. Any other `/admin/*` path redirects to
+ * `AdminHomePath`. People, logs and backups exist in code but stay closed
+ * until they are added back here.
+ */
+export const AdminSections = ["/admin/bots", "/admin/settings"] as const;
+
+export const AdminHomePath = "/admin/bots";

src/dict/bot-dict.ts

@@ -48,6 +48,12 @@ export const BotKinds = [
 
 export type BotKind = (typeof BotKinds)[number]["value"];
 
+/**
+ * Every workspace has exactly one coordinator, created with the account. It
+ * coordinates the crew and hands work to the other bots.
+ */
+export const CoordinatorBotName = "Coordinator";
+
 /**
  * A bot's face is its status. There are no badges or spinners.
  */

src/dict/settings-pages-dict.ts

@@ -0,0 +1,32 @@
+import {
+    KeyRound,
+    SlidersHorizontal,
+    UserRound,
+    type LucideIcon,
+} from "lucide-react";
+
+export type SettingsPage = {
+    title: string;
+    url: string;
+    Icon: LucideIcon;
+};
+
+/**
+ * The `/admin/settings/*` sub pages, listed in the rail on every settings
+ * page. The first one is where `/admin/settings` lands.
+ */
+export const SettingsPages: SettingsPage[] = [
+    {
+        title: "General",
+        url: "/admin/settings/general",
+        Icon: SlidersHorizontal,
+    },
+    { title: "Profile", url: "/admin/settings/profile", Icon: UserRound },
+    {
+        title: "Change password",
+        url: "/admin/settings/change-password",
+        Icon: KeyRound,
+    },
+];
+
+export const SettingsDefaultPath = "/admin/settings/general";

src/dict/theme-preferences-dict.ts

@@ -0,0 +1,29 @@
+import { Monitor, Moon, Sun, type LucideIcon } from "lucide-react";
+
+export const ThemePreferences = [
+    {
+        title: "System",
+        value: "system",
+        description: "Follows your device",
+        Icon: Monitor,
+    },
+    {
+        title: "Light",
+        value: "light",
+        description: "Paper and ink",
+        Icon: Sun,
+    },
+    {
+        title: "Dark",
+        value: "dark",
+        description: "Easy at night",
+        Icon: Moon,
+    },
+] as const satisfies {
+    title: string;
+    value: string;
+    description: string;
+    Icon: LucideIcon;
+}[];
+
+export type ThemePreference = (typeof ThemePreferences)[number]["value"];