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/schemas/bot-schema.ts

@@ -0,0 +1,12 @@
+import { z } from "zod";
+
+export const SendBotMessageRequestSchema = z.object({
+    bot_id: z.coerce.number().int().positive("Pick a bot to message"),
+    text: z
+        .string()
+        .trim()
+        .min(1, "Write a message first")
+        .max(4000, "Keep messages under 4000 characters"),
+});
+
+export type SendBotMessageRequest = z.infer<typeof SendBotMessageRequestSchema>;