feba2fe7b7
- adapters/__init__.py: add http_get() unified retry helper + AdapterHTTPError + failure_class classification (429/5xx/4xx/error/zero_fetch/ok) + last_failure_class on SourceAdapter for pipeline capture - pipeline.py: ENABLED_SOURCES now includes RSS + failure_class rollup in run_log (most severe across all adapters) + per-source failure_class in source_stats - schema.sql: add failure_class column to run_log table Backport of fix/adapter-health-1-2-9 branch (issues #1, #2, #9).