chore(matrix): final scrub of stale matrix references

A grep audit after the previous matrix removal commits found a handful
of stragglers in non-runtime files that the earlier sweeps missed:

- services/mana-llm/CLAUDE.md: removed matrix-ollama-bot from the
  consumer-apps diagram and from the related-services table
- services/mana-video-gen/CLAUDE.md: removed "Matrix Bots" integration
  bullet
- packages/notify-client/README.md: removed sendMatrix() doc entry
  (the method itself was already gone in the prior cleanup)
- docker/grafana/dashboards/logs-explorer.json: dropped the "Matrix
  Stack" log row that queried tier="matrix" (would show no data forever)
- docker/grafana/dashboards/master-overview.json: dropped the "Matrix
  Bots" stat panel that counted up{job=~"matrix-.*-bot"}
- apps/mana/apps/landing/src/data/ecosystem-health.json: regenerated via
  scripts/ecosystem-audit.mjs to drop matrix from the app list, icon
  counts, file analytics, top offenders and authGuard missing list
- .gitignore: removed services/matrix-stt-bot/data/ pattern (the
  service itself was deleted long ago)

Production-side stragglers also addressed (not in this commit):
- DROP USER synapse on prod Postgres (the parallel cleanup commit
  2514831a3 dropped DATABASE matrix + DATABASE synapse but left the
  role behind)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitignore

@@ -129,5 +129,4 @@ pip-delete-this-directory.txt
 
 # ML Models (large files, downloaded on demand)
 mlx_models/
-services/matrix-stt-bot/data/
 services/mana-sync/server