DNS single-source Phase 1 + decommission Tailscale fleet-wide

Phase 1 of the DNS-redundancy cleanup (keep NetBird, collapse toward one
zone) — the safe, mesh-independent half:

- Every homelab LXC now resolves via Technitium (192.168.8.2). Fixed 8
  boxes on a dead resolver (.180), the router (.1), or Tailscale MagicDNS
  (100.100.100.100): 101,102,104,105,106,114,119,126.
- Removed the redundant /etc/hosts auth/mcp/secrets overrides (Technitium
  returns identical-or-better answers); disabled hubris-hosts-override.
- Net effect: on-prem DNS (LXCs + household via Fritz!Box->Technitium) is
  now NetBird-independent, so dropping the managed zone later can't break
  on-LAN resolution. Phases 2-4 still pending.

Tailscale decommissioned (was legacy/being-phased-out):
- Removed from the 6 LXCs still running it (101,103,104,105,114,119):
  logout, disable tailscaled, apt purge, state cleared.
- inventory.yaml: dropped tailscale from accepted + all mesh blocks;
  regenerated hosts/*.yaml (also pruned orphan authentik/claudio-bot).
- Tightened secrets-issuance MESH_SUBNETS: removed the now-vestigial
  Tailscale CGNAT range 100.64.0.0/10.
- Updated narrative docs (mesh, dns, network, README, AGENTS,
  agent-enrollment, homelab-context, 105-apps, 107-dns).

Live infra changed on the fleet + Mac; this commit records the docs/inventory.

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

infrastructure/mesh.md

@@ -1,12 +1,12 @@
-# Mesh — Tailscale → Netbird migration
+# Mesh — Netbird
 
-The hubris fleet is migrating from Tailscale to Netbird. Netbird is the target end-state. In-progress as of 2026-04-21.
+The hubris fleet runs on Netbird. Tailscale — the previous overlay — was **fully decommissioned on 2026-06-21**: removed from the 6 LXCs that still ran it (101, 103, 104, 105, 114, 119), apt package + state purged, `tailscaled` disabled. The fleet is now Netbird-only. (Historical migration notes below are kept for context.)
 
 ## Current state
 
 - **PVE host** uses Netbird (`wt0`, `100.122.38.109/16`). Its resolver is the local netbird daemon, which forwards to LAN/upstream — so the PVE host gets `*.hubris.network → 192.168.8.175` via the system resolver chain.
 - **Netbird mgmt host** (`82.165.190.79`, FQDN `inspiring-ramanujan.netbird.selfhosted`, NB IP `100.122.165.149`) is now itself a peer on the mesh (joined 2026-04-22 via setup key, netbird 0.69.0). Routes the homelab network (`192.168.8.0/24`) via the PVE peer. This gives the mgmt host LAN access *and* split-horizon DNS for `*.hubris.network`. Useful independently of any Authentik integration.
-- **Most LXCs** still run Tailscale or use router DNS (`192.168.8.1`) / Tailscale MagicDNS (`100.100.100.100`), both of which return the *public* IONOS A record `*.hubris.network → 82.165.190.79`. The VPS only routes hostnames it actually publishes (today, `artifacto` + `blog`), so this path is a dead end for any LAN-only service.
+- **All LXCs** now resolve via Technitium (`192.168.8.2`) directly — as of the 2026-06-21 DNS single-source work (Phase 1). The previous mix of router DNS (`192.168.8.1`) / Tailscale MagicDNS (`100.100.100.100`) returned the *public* IONOS A record and is gone. See [dns.md changelog 2026-06-21](dns.md).
 
 ## ICE / STUN / TURN
 
@@ -45,6 +45,8 @@ Pre-migration, the bundled `netbirdio/netbird-server` combined image silently ig
 
 ## Consequence — every LXC wired to Authentik needs an internal override
 
+> **RESOLVED 2026-06-21 (DNS single-source, Phase 1).** Every homelab LXC now points its resolver directly at **Technitium (`192.168.8.2`)**, which answers the full split-horizon zone (`auth → 82.165.190.79`, everything else → Caddy `192.168.8.175`). The per-LXC `/etc/hosts` overrides and Tailscale-MagicDNS/dead-`.180`/router resolvers below were removed; `hubris-hosts-override.service` disabled where present. The section is kept for history. See [dns.md changelog 2026-06-21](dns.md).
+
 Until each LXC is migrated to Netbird, anything that needs to reach `auth.hubris.network` (Authentik), `cloud.hubris.network` (Nextcloud), etc., must override the public answer with `192.168.8.175`.
 
 Two techniques. Pick by HTTP-client behavior.
@@ -90,7 +92,7 @@ pct set <id> --nameserver "127.0.0.1 192.168.8.1 1.1.1.1"
 ## Adding new LXCs
 
 - Don't add new LXCs to Tailscale; add them to Netbird. Tailscale is being decommissioned on hubris.
-- When wiring a new app into Authentik: `cat /etc/resolv.conf` on the target LXC. If nameserver is `192.168.8.1` or `100.100.100.100`, add the hosts override. If it's the netbird daemon IP, skip.
+- When wiring a new app into Authentik: `cat /etc/resolv.conf` on the target LXC. It should be `192.168.8.2` (Technitium), which returns correct split-horizon answers — no `/etc/hosts` override needed. (Historically, boxes on `192.168.8.1`/`100.100.100.100` needed an override; those resolvers were removed 2026-06-21.)
 
 ## Long-term fix