feat(ingest): add STORE_MIN_SEVERITY second-tier severity gate

[aksOps]

Summary

Adds a second log-severity threshold (STORE_MIN_SEVERITY) that runs at the persist boundary inside the async ingest pipeline. Logs above INGEST_MIN_SEVERITY but below STORE_MIN_SEVERITY are dropped from the BatchCreateAll write — but they still flow through LogCallback, so vectordb indexing, GraphRAG Drain template mining, and span/trace correlation keep seeing them.

Use case

"I want DEBUG/INFO logs to enrich my in-memory anomaly detection but I don't want them bloating SQLite."

INGEST_MIN_SEVERITY=DEBUG STORE_MIN_SEVERITY=WARN

DEBUG → reaches receiver, fires LogCallback, NOT persisted.
WARN/ERROR → reaches receiver, fires LogCallback, persisted normally.

Backwards compatibility

Default (STORE_MIN_SEVERITY="") means "use the same threshold as INGEST_MIN_SEVERITY" — the gate is a no-op out of the box. Setting STORE_MIN_SEVERITY ≤ INGEST_MIN_SEVERITY is also a no-op (logged as a warning at startup since the receiver has already filtered).

Implementation

File	Change
internal/config/config.go	Add StoreMinSeverity field + STORE_MIN_SEVERITY env
internal/ingest/pipeline.go	storeMinSeverity field, SetStoreMinSeverity setter, filter inside process() that splits b.Logs into persisted vs callback-only, atomic StoreFiltered counter exposed via PipelineStats
internal/ingest/otlp.go	Export ParseSeverity wrapper so main.go can translate the env value
main.go	Parse both thresholds; only enable the gate when store > ingest; warn on misconfig
CLAUDE.md	Document both thresholds with the use-case example

Observability

Pipeline.Stats().StoreFiltered (int64) — count of logs dropped from persist by the store gate. Available via the existing pipeline stats accessor.

Test plan

• TestPipeline_StoreMinSeverity_DropsBelowThresholdFromPersist — WARN gate drops INFO from persist; INFO still reaches LogCallback; StoreFiltered=1
• TestPipeline_StoreMinSeverity_Disabled_PersistsAllLogs — legacy path unchanged when SetStoreMinSeverity not called
• go vet ./... clean
• go build ./... clean
• go test -race -timeout 180s ./... — 518 passed in 28 packages (+2 new)
• CI green
• SonarCloud Quality Gate green

🤖 Generated with Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud