Mirrors PR #429 for the planner app. Each HTTP request now gets a
requestId (inbound X-Request-Id honored, otherwise a fresh UUID),
echoed on the response, and propagated to every downstream log call via
AsyncLocalStorage + pino's \`mixin\`.
Tests: planner logger.server.test.ts (2 cases, same shape as the
journal version).
Full repo: pnpm typecheck, pnpm lint, pnpm test all green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
