feat(02-01): bot workspace scaffold with Env contract (D-09/D-10/D-11/D-15)

- bot/ npm workspace sibling to theme/: grammy ^1.46.0, wrangler ^4.151.3, TS ^5.9.3
- src/config.ts exports Env (BOT_TOKEN, WEBHOOK_SECRET, chat_sessions KVNamespace)
- wrangler.jsonc: main src/webhook.ts + chat_sessions KV binding (id filled in plan 03)
- .gitignore ships .dev.vars/.wrangler/ in the same commit as .dev.vars.example (D-17)
- root delegate scripts bot:test/typecheck/dev/deploy/commands

bot/tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "target": "ES2023",
+    "lib": ["ES2023"],
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "types": ["@cloudflare/workers-types"],
+    "strict": true,
+    "noUncheckedIndexedAccess": true,
+    "verbatimModuleSyntax": true,
+    "allowImportingTsExtensions": true,
+    "noEmit": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true
+  },
+  "include": ["src"]
+}