Use strconv.FormatInt/FormatUint instead of fmt.Sprintf for integer
conversions in snmpValueToString. Use encoding/hex + strings.Builder
instead of fmt.Sprintf loop in formatHex. Use strconv.FormatUint for
WebSocket ref counter. Reduces allocations per OID significantly.
Previously each OID was fetched individually, meaning 1000 OIDs
required 1000 round trips. Now OIDs are batched into groups of 60
(the SNMP max PDU size), reducing round trips by ~50x. Also
pre-sizes the OID value map to avoid repeated rehashing.
- Dockerfile: add BuildKit cache mounts for Go module and build caches,
pin both stages to Alpine 3.23
- CI: replace BUILDKIT_INLINE_CACHE with registry-based layer caching
(mode=max) for branch and release builds
- .dockerignore: exclude test files, Rust legacy, nix, and other
non-build artifacts from Docker context
- SNMP: lower MaxRepetitions from default 50 to 10 to prevent Mikrotik
routers from timing out during bulk walks
