Phase 6: theme trend-scan (B) + competitor gap research (A)

- theme_scan.py: tags entries by 4 practitioner themes (tool-call/context/
  compute/trust), counts NEW arrivals per cron cycle (falsification check for
  one-day-cluster vs trend). Idempotent: re-run = 0 new.
- schema.sql: theme_tags table (separate from core entries schema)
- oracle-pipeline.sh: wire theme_scan after summarize
- A result (footnote): unified discipline layer unoccupied; adjacent OSS
  entrants exist (agentgateway, lelu) but no portable unified layer.

Verified: theme_scan classifies 5 seed/extra items, 2nd run = 0 new.

oracle-pipeline.sh

@@ -21,6 +21,9 @@ cd "$ORACLE_DIR" || { echo "FATAL: cannot cd $ORACLE_DIR"; exit 1; }
   echo "=== Summarization Engine ==="
   python3 summarize.py
   echo
+  echo "=== Phase 6 theme trend scan (new arrivals this cycle) ==="
+  python3 theme_scan.py
+  echo
   echo "=== Soft-cap archive (dry-safe default: 30d / 5000 cap) ==="
   python3 archive.py --days 30 --cap 5000
   echo