archive: remove entire archive/ directory and all references

archive/ contained the old narrative wiki (superseded by DB as source
of truth), hermes-plans, oikos-cards, ledger, secrets-issuance, and
SOPS backups — all Python-era artifacts with no ongoing value.

Updated all cross-references in:
- AGENTS.md, README.md
- .agents/operations/commands.md (point to docs/infrastructure/)
- .agents/shared/llm-wiki.md, page-templates.md
- .agents/domains/knowledge/schema.md, operations/schema.md
- .agents/skills/*/SKILL.md
- docs/infrastructure/*.md (removed archive link targets)
- docs-lint/SKILL.md known-baseline note

AGENTS.md

@@ -24,7 +24,8 @@ structured data and knowledge. It is bootstrapped from `seeds/` at deploy time:
 `seeds/ontology.yaml` (entity types, relationships, lifecycles), `seeds/inventory.yaml`
 (hosts, services, entities), `seeds/policy.yaml` (risk classes, approval rules), and
 `seeds/knowledge.yaml` (documents, investigations, runbooks). The old narrative wiki
-is archived at `archive/knowledge/` for historical reference.
+was archived at `archive/knowledge/` for historical reference (since deleted — the DB is
+the sole source of truth).
 
 ## 1. Who you are
 
@@ -169,8 +170,8 @@ POST /api/v1/knowledge/{entity_slug}
 {"title": "...", "content": "...", "tags": ["..."]}
 ```
 
-The DB is the truth. The old wiki files are archived at `archive/knowledge/`
-(historical reference only — use MCP `search_knowledge` for live queries).
+The DB is the truth. The old wiki files were archived at `archive/knowledge/`
+(historical reference only — since deleted; use MCP `search_knowledge` for live queries).
 
 - **Runbook procedures** live as `runbook` entities in the DB and as SKILL.md
   files under `.agents/skills/<name>/`. They carry `risk_class`, `procedure`