feat(server): add OpenTelemetry tracing and metrics support

Adds comprehensive OpenTelemetry instrumentation for better observability:

Tracing:
- HTTP requests via @opentelemetry/instrumentation-http
- NestJS controllers via @opentelemetry/instrumentation-nestjs-core
- Redis operations via @opentelemetry/instrumentation-ioredis
- BullMQ job queues via bullmq-otel
- Database queries via Kysely log callback with accurate timing
- File operations (send, stream, read)
- Media processing (thumbnails, thumbhash, EXIF operations)
- Metadata extraction

Metrics:
- Database connection pool usage (used/idle connections)

The SDK is initialized in telemetry-preload.ts which is preloaded via
--require before the main app starts. This ensures http instrumentation
hooks are in place before any http module is imported.

Enable tracing by setting OTEL_EXPORTER_OTLP_ENDPOINT environment variable.

Also adds TraceContext to IBaseJob for future distributed trace propagation
across BullMQ job boundaries.

server/bin/immich-dev

@@ -6,4 +6,17 @@ if [[ "$IMMICH_ENV" == "production" ]]; then
 fi
 
 cd /usr/src/app || exit
+
+# Compile telemetry-preload so it can be required before the app starts.
+# This is necessary for OpenTelemetry http instrumentation to work correctly.
+mkdir -p dist
+pnpm --filter immich exec tsc src/telemetry-preload.ts \
+  --outDir dist \
+  --esModuleInterop \
+  --module node16 \
+  --moduleResolution node16 \
+  --target ES2022 \
+  --skipLibCheck
+
+export NODE_OPTIONS="${NODE_OPTIONS} --require ./dist/telemetry-preload.js"
 pnpm --filter immich exec nest start --debug "0.0.0.0:9230" --watch -- "$@"