docs: streamline & consolidate the tree (phase 6)

Problem: after the wiki-hq reorg, agent-instruction and human-doc domains
were still scattered across the repo root, with three now-redundant stub
files cluttering it. The organizing principle wasn't visible in the layout.

Change — enforce three clear buckets:
- .agents/  = how agents operate: OIKOS.md, HERMES.md (moved from root),
  shared/ conventions, domains/ schemas, skills/, and operations/ (operator
  cheatsheet + enrollment + hermes-agent, moved from root).
- knowledge/ = what exists + evidence: wiki/, GLOSSARY.md, and sources/ now
  including investigations/ (incident records are evidence/sources).
- root = substrate + two entry points (AGENTS.md, README.md), plus plans/
  as its own design-intent domain.

Moves:
- investigations/ -> knowledge/sources/investigations/ (incl. archive/, index).
- operations/ -> .agents/operations/.
- HERMES.md -> .agents/HERMES.md.
- Deleted unreferenced root stubs CAVEMAN.md, CONTRIBUTING.md, and OIKOS.md
  (its 7 remaining linkers repointed to .agents/OIKOS.md).

Consumers updated:
- inventory.yaml doc_page (agent-enrollment) + regenerated hosts/*.yaml + cards.
- tools/setup-hermes-soul.sh and bootstrap.sh (x2) -> .agents/HERMES.md.
- bin/homelab help string -> .agents/operations/hermes-agent.md.
- knowledge/operations schemas, llm-wiki, page-templates, incident-investigation
  skill, AGENTS.md/README nav -> new investigations/operations paths.
- All markdown links rewritten via the path-resolving mapper.

Left in place (substrate/executable/separate-domain): hosts/, ledger/, tools/,
plans/, oikos/, mcp/, secrets/, bin/, inventory.yaml.

Verification: docs-lint at baseline (2 intentional cross-repo refs, no new
breakage); gen-topology.py --check exit 0; build_host_files.py idempotent; all
doc_page targets resolve; Hermes provisioning scripts point at the new path.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

knowledge/wiki/infrastructure/dns.md

@@ -110,7 +110,7 @@ All LXCs that Caddy reverse-proxies to by IP were on `ip=dhcp` and could float o
 Split-horizon DNS moved off [124](../containers/106-auth-outpost.md) to a dedicated **Technitium** LXC at **`192.168.8.2`** (zone: specific A overrides + wildcard→VPS + replicated MX/SPF/CAA). NetBird `home-lab-dns` nameserver group cut over to `192.168.8.2` (with `.180` as a now-dead fallback). dnsmasq stopped, all names verified via Technitium, **LXC 124 shut down**. **Caveat:** the [NetBird managed DNS zone](../containers/106-auth-outpost.md) still answers most app names *directly* (bypassing the nameserver group) — three overlapping DNS sources remain; see the single-source-of-truth decision (Phase 4). **Action needed:** update router DHCP DNS from the dead `.180` → `192.168.8.2` for any plain-LAN (non-mesh) clients.
 
 ### 2026-05-31 — `auth.hubris.network` re-pointed to the VPS (`82.165.190.79`)
-Authentik migrated off LXC 124 onto the VPS (see [investigation](../../../investigations/archive/2026-05-31-authentik-vps-migration.md)). The dnsmasq entry changed from `192.168.8.175` (home Caddy) to `82.165.190.79` (VPS traefik). This is the first LAN entry that intentionally points at the VPS rather than Caddy — `auth` is now a genuinely public service served directly from the VPS. **Gotcha logged:** the NetBird per-client resolver (`100.122.255.254`) caches dnsmasq answers and does **not** clear on `netbird down/up`; clients needed `/etc/hosts` overrides or `resolvectl flush-caches` to pick up the change. Since the service is now fully public, the long-term cleaner option is to drop the override entirely and let it fall through to the IONOS wildcard (which also points at the VPS).
+Authentik migrated off LXC 124 onto the VPS (see [investigation](../../sources/investigations/archive/2026-05-31-authentik-vps-migration.md)). The dnsmasq entry changed from `192.168.8.175` (home Caddy) to `82.165.190.79` (VPS traefik). This is the first LAN entry that intentionally points at the VPS rather than Caddy — `auth` is now a genuinely public service served directly from the VPS. **Gotcha logged:** the NetBird per-client resolver (`100.122.255.254`) caches dnsmasq answers and does **not** clear on `netbird down/up`; clients needed `/etc/hosts` overrides or `resolvectl flush-caches` to pick up the change. Since the service is now fully public, the long-term cleaner option is to drop the override entirely and let it fall through to the IONOS wildcard (which also points at the VPS).
 
 ### 2026-05-14 — `nfs-export.hubris.network` added (direct, non-HTTP)
 NFSv4 export server [nfs-export (102)](../containers/102-nfs-export.md) at `192.168.8.200`. Direct entry, not Caddy-fronted — NFS is L4, no HTTP reverse-proxy meaningful.