refactor: migrate discord-gateway from winston to @bete/shared/logger and utils

- Replace all local logger imports (../../shared/logger/logger.js) with @bete/shared/logger across 26 files
- Remove winston dependency, add pino to discord-gateway package.json
- Delete shared/logger/logger.ts (winston-based, 132 lines) and serialization.ts (109 lines)
- Replace local retryWithBackoff imports with @bete/shared/utils across 6 files
- Delete shared/utils/retry.ts (42 lines)
- Add CustomLogger type alias to @bete/shared/logger for backwards compatibility
- Remove logger param from all retryWithBackoff calls and uploadToTele interfaces
- Frontend: convert entity type files to re-exports from shared/api/client.ts
- Full monorepo typecheck clean (4/4 packages)

35 files changed, 42 insertions(+), 488 deletions(-)

services/discord-gateway/package.json

@@ -30,10 +30,10 @@
     "p-limit": "^7.3.0",
     "p-retry": "^8.0.0",
     "pg": "^8.21.0",
+    "pino": "^9.6.0",
     "piscina": "^5.1.4",
     "prism-media": "2.0.0-alpha.0",
     "sharp": "^0.34.5",
-    "winston": "^3.19.0",
     "ws": "^8.20.1",
     "zod": "^4.4.3"
   },