- Implement computeCounterDelta for Counter32/Counter64 with wraparound handling
- Sanity threshold discards deltas > 90% of max value (device reset detection)
- CounterCache uses Redis MGET/MSET pipelining for efficient state persistence
- Counter keys use "snmp:counter:{device_id}:{oid}" format with 600s TTL
- Add SNMPMetricsEvent and SNMPMetricEntry structs to bus package
- Add PublishSNMPMetrics publishing to "device.metrics.snmp_custom.{device_id}"
- Full test coverage: 10 counter tests including miniredis integration
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Install gosnmp v1.43.2 as direct dependency
- Create snmp package with SNMPConfig, CompiledProfile, PollGroup types
- Implement BuildSNMPClient for v1, v2c, and v3 (all security levels)
- Map auth protocols (MD5, SHA, SHA224-512) and priv protocols (DES, AES128-256)
- MaxRepetitions set to 10 (not gosnmp default 50) for embedded devices
- Full test coverage: 9 tests covering all SNMP versions and protocol mappings
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>