N0: rename Hermes → Nomos (standalone commit)

Problem: "Hermes" collides with Nous Researchs unrelated product;
  unclear identity for the resident agent.

  Change: Rename the live service identity across 39 files:
  - cmd/hermes/ → cmd/nomos/ (binary, env vars NOMOS_*)
  - internal/config/ server.go (NomosAgentSlug, nomosAgentID)
  - compose/hermes/ → compose/nomos/ (Dockerfile, service name)
  - hermes/ → nomos/ (SOUL.md, config.yaml, skills/)
  - .agents/HERMES.md → NOMOS.md (persona)
  - tools/setup-hermes-soul.sh → setup-nomos-soul.sh
  - seeds/inventory.yaml (agent:hermes → agent:nomos)
  - migrations/014_rename_agent_hermes_to_nomos.up.sql
  - Caddy vhost hermes.hubris.network → nomos.hubris.network
  - All referencing docs, scripts, ADR notes

  History preserved: archive/, plans/done/, ADRs not rewritten.
  Matrix @hermes notifier account and Legacy bin/hermes on LXC 129
  intentionally untouched (out of scope).

  Risk: N0 is identity-only rename; zero behavioral changes.
  Verification: go build ./... passes; docker compose --profile full
  resolves nomos service; grep -ri hermes (excluding archive/plans)
  returns only intentional refs (LLM model name, Matrix user).

migrations/014_rename_agent_hermes_to_nomos.up.sql

@@ -0,0 +1,18 @@
+-- 014_rename_agent_hermes_to_nomos.up.sql
+-- Rename the Hermes agent entity to Nomos (N0 milestone).
+-- Identity-preserving: the UUID, relationships, and audit history survive.
+-- The matching seed upsert will no-op because it upserts by slug.
+
+DO $$
+BEGIN
+    IF EXISTS (SELECT 1 FROM entities WHERE slug = 'agent:hermes') THEN
+        UPDATE entities
+        SET slug = 'agent:nomos',
+            name = 'nomos',
+            attributes = jsonb_set(attributes, '{name}', '"nomos"'),
+            updated_at = now()
+        WHERE slug = 'agent:hermes'
+          AND NOT EXISTS (SELECT 1 FROM entities WHERE slug = 'agent:nomos');
+    END IF;
+END
+$$;