feat: scaffold worker application shell

Adds apps/worker with TypeScript config, BullMQ/ioredis dependencies,
pino logger bootstrap, and a smoke test. Queue consumers wired in later phases.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/worker/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "./dist",
+    "rootDir": "./src"
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}