[anurag629]

T10 for the docs site (F-03 task 14, the bot half). The docs chat is the first real user of the new packages.

• With a CHATCOPS_DB D1 binding, the chat uses cloudflareStorage({ d1 }), so conversations, rate limits and turn locks hold across every isolate, with 30-day retention. Without the binding, it stays in memory as today. That means this can merge before the database exists.
• With a CHATCOPS_SESSION_SECRET secret, session tokens are on. requireSession stays false while pre-0.6 widgets are still cached. The new src/pages/api/chat/session.ts route serves /api/chat/session.
• The website depends on @chatcops/store-cloudflare from the workspace, so it does not wait for the npm publish.
• cloudflare:workers gets a small type declaration for the one env the page reads.

Two things need the maintainer: creating the D1 database, after which a one-line d1_databases entry goes into wrangler.jsonc in a follow-up, and setting the session secret on the Worker.

Checks: the website builds and typechecks, and lint is at the dev baseline. Locally, astro dev streams a reply on /api/chat without the binding, and /api/chat/session answers 404 with sessions off.