Fix Pino Logger Double-Logging and Sync I/O

[foxintheloop]

Problem

apps/mcp-server/src/logger.ts double-logs everything — once via pino (stderr) and once via synchronous appendFileSync. The sync file I/O blocks the Node.js event loop on every log call.

Solution

1. Replace appendFileSync with pino's multi-transport using targets array for async file writing via worker threads
2. Add log rotation via pino-roll (daily rotation, keep 7 days)
3. Use pino child loggers instead of the custom createScopedLogger wrapper
4. Follow pino convention: data as first arg, message as second: logger.info({ tool, duration }, 'Tool completed')

Files

• apps/mcp-server/src/logger.ts — rewrite logging infrastructure