Remove operator auth — trust the LAN

Can't log in from a fresh LXC deploy, and the service is LAN-only by
design. Rip out the whole bcrypt-password / signed-cookie session
layer: internal/auth, login templates, gen-admin-password binary +
Makefile targets, auth config block, login/logout routes and the
RequireSession middleware wrap. Agent bearer-token auth on
/api/v1/runs/{id}/* is untouched.

Operators who want a password can front the service with a reverse
proxy — noted in README and docs/operations.md.

docs/architecture.md

@@ -45,7 +45,6 @@ Operator browser (HTMX + SSE, admin login)
 | `internal/api` | HTTP handlers: `agent_handlers.go` (the agent-facing API) and `ui_handlers.go` (HTMX fragments + SSE). |
 | `internal/httpserver` | chi router assembly — lives here to avoid `api ↔ orchestrator` cyclic imports. |
 | `internal/web` | Embedded static assets + compiled Templ templates. |
-| `internal/auth` | Single-admin bcrypt + signed-cookie sessions. |
 | `internal/pxe` | dnsmasq subprocess supervisor + per-MAC iPXE script generator. |
 | `internal/events` | In-process SSE hub (fan-out to live browser clients). |
 | `internal/logs` | Per-run flat-file writer + SSE fan-out of live log tail. |

docs/operations.md

@@ -37,25 +37,18 @@ repaired nodes so DHCP and WoL work.
    - disables the distro-default dnsmasq (the orchestrator supervises
      its own)
 
-   The installer does **not** enable the service, because the default
-   config has a placeholder bcrypt password that the binary refuses to
-   start with.
+   The installer does **not** enable the service. You'll want to edit
+   the config first.
 
-3. Generate an admin password hash and a session secret, then edit
-   `/etc/vetting/vetting.yaml`:
+3. Edit `/etc/vetting/vetting.yaml`:
 
-   ```
-   ./bin/gen-admin-password 'your-password-here'       # prints a bcrypt hash
-   openssl rand -hex 32                                 # prints a 64-char hex string
-   ```
-
-   Required fields:
-   - `auth.admin_password_bcrypt` — the bcrypt hash
-   - `auth.session_secret_hex` — the 32-byte hex string
+   - `server.bind` — defaults to `127.0.0.1:8080`. Switch to
+     `0.0.0.0:8080` (or bind to a specific LAN IP) once you're ready
+     to expose it. There is no built-in auth — see *Exposing outside
+     the LAN* below.
    - `server.public_url` — the URL your browser hits the LXC on
-     (e.g. `https://vetting.lan:8443`). This is used as the
-     click-through link in notifications, so it must be the *external*
-     URL, not the bind address.
+     (e.g. `http://vetting.lan:8080`). Used as the click-through link
+     in notifications.
 
 4. (Optional) Configure notifiers in the same file — see the
    commented-out example block for ntfy / Discord / SMTP.
@@ -79,7 +72,7 @@ Against a QEMU VM first, before you point it at real hardware:
    sudo ip link set br-vetting up
    ```
 
-2. In the UI at `https://<lxc>:8443`, log in and register a host:
+2. In the UI at `http://<lxc>:8080`, register a host:
    - Name: `qemu-test`
    - MAC: `52:54:00:12:34:56`
    - WoL broadcast IP: `10.77.0.255`
@@ -145,11 +138,19 @@ Retention is governed by the `artifacts.retention_days` and
 `logs.retention_days` settings. DB rows (run history) are preserved
 indefinitely; only on-disk files get pruned.
 
+## Exposing outside the LAN
+
+The orchestrator UI has no built-in auth. It's designed to live on a
+trusted home LAN and trust whatever reaches it. If you want to reach
+it from outside that LAN, don't expose the bind port directly — put
+it behind a reverse proxy (Caddy, nginx, Traefik) that terminates TLS
+and adds basic-auth or OIDC. The agent↔orchestrator bearer token
+auth is independent and keeps working either way.
+
 ## Troubleshooting
 
 | Symptom | First check |
 |---|---|
-| Service refuses to start with `auth.admin_password_bcrypt is the placeholder` | You didn't replace the bcrypt hash in the config. Run `gen-admin-password`. |
 | PXE client gets no DHCP offer | `journalctl -u vetting` for dnsmasq errors; confirm the LXC has `CAP_NET_ADMIN` (the shipped systemd unit does); confirm the host MAC is actually registered (`sqlite3 /var/lib/vetting/vetting.db 'SELECT name, mac FROM hosts;'`). |
 | Agent `/hello` never fires | Check the live image is actually loading the agent binary — SSH into the live env (use the hold key path), `systemctl status vetting-agent`. |
 | Tile stuck on `Booting` | Most likely the live image booted but the agent can't reach the orchestrator. Verify `vetting.orchestrator=` in the kernel cmdline resolves from the host's network. |