db as source of truth: wiki→seeds, archive old artifacts, knowledge ingestion

- Migrations 010 (content_hash) + 011 (search tsvector column)
- new: internal/knowledge/seed.go — knowledge seed ingest engine
- new: internal/httpapi/knowledge.go — SearchKnowledge + GetEntityKnowledge
- wire knowledge ingest into oikos seed pipeline
- convert all 36 wiki docs + 6 investigations + 12 runbooks → seeds/knowledge.yaml
- archive: knowledge/wiki/→archive/, oikos/cards/→archive/, .hermes/plans/→archive/
- delete: 9 superseded Python kernel files, ledger/, mcp/build_host_files.py
- remove empty knowledge/ directory tree

archive/knowledge/vms/index.md

@@ -0,0 +1,14 @@
+# VMs — index
+
+Two QEMU VMs running on [hubris](../hosts/hubris.md):
+
+| ID | Name | Role | IP | Public hostname |
+|----|------|------|----|-----------------|
+| 100 | [zimaos](100-zimaos.md) | NAS frontend eval (ZimaOS) | `192.168.8.195` | [`zimaos.hubris.network`](../infrastructure/dns.md) |
+| 108 | [haos-16.3](108-haos.md) | Home automation (HAOS) | `192.168.8.101` | [`home.hubris.network`](../infrastructure/dns.md) |
+
+## Related
+
+- [Hubris host](../hosts/hubris.md) — both VMs run here
+- [Containers index](../containers/index.md) — LXCs on both nodes
+- [README](../../../README.md)