feat: scaffold plug-n-play telegram bot on cloudflare workers

grammY-based bot with a module plugin system loaded from the MODULES env
var. Three command visibility levels (public/protected/private) share a
unified command namespace with conflict detection at registry build.

- 4 initial modules (util, wordle, loldle, misc); util fully implemented,
  others are stubs proving the plugin system end-to-end
- util: /info (chat/thread/sender ids) + /help (pure renderer over the
  registry, HTML parse mode, escapes user-influenced strings)
- KVStore interface with CFKVStore and a per-module prefixing factory;
  getJSON/putJSON convenience helpers; other backends drop in via one file
- Webhook at POST /webhook with secret-token validation via grammY's
  webhookCallback; no admin HTTP surface
- Post-deploy register script (npm run deploy = wrangler deploy && node
  --env-file=.env.deploy scripts/register.js) for setWebhook and
  setMyCommands; --dry-run flag for preview
- 56 vitest unit tests across 7 suites covering registry, db wrapper,
  dispatcher, help renderer, validators, and HTML escaper
- biome for lint + format; phased implementation plan under plans/

biome.json

@@ -0,0 +1,33 @@
+{
+  "$schema": "https://biomejs.dev/schemas/1.9.0/schema.json",
+  "organizeImports": { "enabled": true },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "recommended": true,
+      "style": {
+        "noNonNullAssertion": "off",
+        "useTemplate": "off"
+      },
+      "suspicious": {
+        "noConsoleLog": "off"
+      }
+    }
+  },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "space",
+    "indentWidth": 2,
+    "lineWidth": 100
+  },
+  "javascript": {
+    "formatter": {
+      "quoteStyle": "double",
+      "semicolons": "always",
+      "trailingCommas": "all"
+    }
+  },
+  "files": {
+    "ignore": ["node_modules", ".wrangler", "dist", "coverage"]
+  }
+}