Build Cobble project structure from the handoff

- Remove the preset document suite (letters, emails, invoices, quotes,
  PDF generation, line items) with its routes, API handlers and tables
- Rebrand to Cobble: site data, Lato, handoff design tokens (light and
  dark) in main.css, brand assets in public/brand, ember stone logo and
  regenerated favicons
- Add bots, bot_messages, bot_tasks and bot_task_steps tables, regenerate
  DB types (BUN_SQLITE_COBBLE_*) and add a sample crew seed (seed:bots)
- Add the chat shell at /admin/bots: rail with pinned coordinator and
  user popover, bottom-anchored conversation with composer, working-on
  panel, and a send-message API scoped to the session user
- Add BotStone and Wordmark components, crew status and relative time
  utils with tests, and update AGENTS.md

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

src/pages/api/auth/signup.tsx

@@ -1,4 +1,4 @@
-import type { BUN_SQLITE_BSQLITE_USERS, BunSQLiteTables } from "@/db/types/db";
+import type { BUN_SQLITE_COBBLE_USERS, BunSQLiteTables } from "@/db/types/db";
 import issueSSOLoginCode from "@/src/functions/backend/auth/issue-sso-login-code";
 import createSignupUser from "@/src/functions/backend/auth/create-signup-user";
 import setUserPassword from "@/src/functions/backend/auth/set-user-password";
@@ -67,7 +67,7 @@ export const handler: BunextAPIRouteHandler<APIResponseObject> = async ({
 
         const existing_email_user = (
             await BunSQLite.select<
-                BUN_SQLITE_BSQLITE_USERS,
+                BUN_SQLITE_COBBLE_USERS,
                 (typeof BunSQLiteTables)[number]
             >({
                 table: "users",
@@ -103,7 +103,7 @@ export const handler: BunextAPIRouteHandler<APIResponseObject> = async ({
 
         const existing_username_user = (
             await BunSQLite.select<
-                BUN_SQLITE_BSQLITE_USERS,
+                BUN_SQLITE_COBBLE_USERS,
                 (typeof BunSQLiteTables)[number]
             >({
                 table: "users",