fix: daemon /run spawn hardening, auth guard before first paint, WS refresh cap, interfaces runtime state

systemd: pre-create volatile /run paths so vacuum-walld's ProtectSystem=strict namespace setup cannot fail with 226/NAMESPACE — RuntimeDirectory=vacuum-wall nginx plus a tmpfiles.d spec (installed to /etc/tmpfiles.d/) covering /run/firewalld and /run/nginx.pid. Drop /run/sudo from ReadWritePaths: NOPASSWD children never need it, and its absence crash-looped restarts after sudo removed /run/sudo.

webui: run the auth session check before mounting the shell so logged-out visitors never flash the sidebar or a protected page; router guard and sidebar now react to auth state, and the login page renders full-bleed.

ws: cap refresh->reconnect episodes at 2 consecutive failures; if the WS path stays dead after a token refresh, abandon reconnection instead of looping refreshAuth forever (UI keeps working via REST until reload).

api: GET /api/network/interfaces now includes loopback and returns per-interface {config, runtime}; dashboard reads runtime.state (carrier counts as up) and the interfaces page filters lo client-side.

daemon: re-collect nginx state after lazy config migration (cached list went stale when the on-disk format changed under it), skip system_import.nginx when config.json already exists (re-parsing vacuum-wall's own generated sites is lossy), and poll nginx (60s) / acme (300s) state so file drift self-heals.

docs/architecture.md

@@ -304,6 +304,8 @@ Both `config/` and `data/` reside within the project directory. The systemd serv
 
 The daemon uses a **runtime directory** at `/run/vacuum-wall` (created by systemd `RuntimeDirectory=`) for secure temporary files during config apply. `tempfile.NamedTemporaryFile` writes to this directory before `sudo cp` moves files to their final destination, eliminating TOCTOU symlink races that would exist with `/tmp`. The directory is automatically removed on service stop.
 
+`/run` is a fresh tmpfs at every boot, so volatile runtime paths must be recreated at startup. This is a hard requirement, not a best practice: with `ProtectSystem=strict`, namespace setup fails (`226/NAMESPACE`) and the unit crash-loops if any `ReadWritePaths=` entry does not exist when the unit spawns. Each `/run` path the daemon references therefore needs a boot-time creator: the unit's `RuntimeDirectory=vacuum-wall nginx` covers the daemon-owned directories, and the `system/tmpfiles.d/vacuum-wall.conf` spec (installed to `/etc/tmpfiles.d/`) pre-creates `/run/firewalld` at early boot via `systemd-tmpfiles-setup.service` (in practice firewalld creates it itself, and it starts before the daemon). `/run/sudo` is deliberately *not* in the unit's `ReadWritePaths=`: the daemon's sudo children use the NOPASSWD whitelist and never read or write sudo's session directory, so listing it only added a boot-time and restart-time failure mode (sudo removes `/run/sudo` when the last session ends).
+
 ## File System Layout
 
 The following file system locations are used for integration with system services:
@@ -317,6 +319,9 @@ The following file system locations are used for integration with system service
 | `/etc/systemd/network/50-<name>.network` | Generated systemd-networkd drop-in files. Written from `config/network/config.json`, one per interface. | Vacuum Wall (lib/network.py) |
 | `/etc/sudoers.d/vacuum-walld` | Sudo whitelist for the daemon user. Defines all permitted privilege escalations. | Install script (rendered from Jinja2 template) |
 | `/run/vacuum-wall` | Runtime directory for secure temp files during config apply (nginx, dnsmasq). Created by systemd `RuntimeDirectory=`, removed on stop. | Daemon (systemd unit) |
+| `/run/nginx` | Runtime directory referenced by the daemon's `ReadWritePaths=`; must exist at spawn. Created by systemd `RuntimeDirectory=` before namespace setup. | Daemon (systemd unit) |
+| `/run/firewalld` | Root-owned runtime dir of firewalld. Must exist at spawn because of `ProtectSystem=strict` + `ReadWritePaths=` (see volatile-/run note above). Present while firewalld runs; also pre-created at early boot by `system/tmpfiles.d/vacuum-wall.conf`. | firewalld / systemd-tmpfiles (early boot) |
+| `/run/sudo` | sudo's session directory. Present only while sudo sessions exist. **Not** in the unit's `ReadWritePaths=` (NOPASSWD sudo children never need it) — see volatile-/run note above. | sudo (created/removed on demand) |
 | `data/auth.db` | SQLite database: users, permissions, token_blacklist, webauthn_creds. Created on first access via `get_db()`. | Auth layer (lib/db.py) |
 
 The `/etc/nginx/conf.d/vacuum-wall.conf` include file ensures that all domain-specific configurations in `sites-enabled/` are loaded by nginx without modifying the main `nginx.conf`. The SSL snippet keeps TLS settings consistent across all managed domains and allows global updates from a single location.