feat(desktop): runtime-configurable backend server address

The desktop shell is one generic .deb/.AppImage distributed via
mca/public_releases, not built per-booth, but the backend origin was baked
in at build time (VITE_API_BASE, hardcoded to http://127.0.0.1:3000) — the
same installer could never point at a different appliance without a
rebuild.

Adds ConnectScreen (shown before Login in Tauri when no backend is saved),
backed by tauri-plugin-store persisting the operator-entered URL across
restarts. CSP's connect-src tightens to 'self' only — all backend traffic
already routes through tauri-plugin-http/websocket, which run Rust-side
and are outside connect-src's reach anyway — and the real access boundary
moves to capabilities/default.json's http:default scope, wildcarded so an
operator-chosen host is actually reachable. Adds a "Change server" control
in Setup (desktop-only) to repoint an already-configured install.

While tracing the desktop auth path for this: tauri-plugin-http's fetch()
runs through Rust's reqwest, which keeps its own cookie jar separate from
the webview, so document.cookie on tauri://localhost never sees the
parking_csrf cookie the server sets (open upstream bug,
tauri-apps/tauri#13045/#11518). This means the desktop app has likely been
silently sending no CSRF header on every mutation since the shell was
first built — pre-existing, independent of this change. Fixed by having
sessionView() (routes/auth.ts) also echo the CSRF value in the login/me
JSON body; the desktop client stashes it in memory and echoes that instead
of reading document.cookie. assertCsrf() itself is untouched.

Verified end-to-end against a real LAN-bound dev server: login returns a
csrfToken matching the cookie, a mutation using the body-sourced token in
X-CSRF-Token succeeds (200), and the same mutation without it still
correctly 403s.

apps/desktop/src-tauri/Cargo.lock

@@ -2305,6 +2305,7 @@ dependencies = [
  "tauri-build",
  "tauri-plugin-http",
  "tauri-plugin-process",
+ "tauri-plugin-store",
  "tauri-plugin-updater",
  "tauri-plugin-websocket",
 ]
@@ -3793,6 +3794,22 @@ dependencies = [
  "tauri-plugin",
 ]
 
+[[package]]
+name = "tauri-plugin-store"
+version = "2.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6708afbe549f176b712066e71648ba8fafba20789453718260c7ca356733cb0c"
+dependencies = [
+ "dunce",
+ "serde",
+ "serde_json",
+ "tauri",
+ "tauri-plugin",
+ "thiserror 2.0.18",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "tauri-plugin-updater"
 version = "2.10.1"
@@ -4301,9 +4318,21 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "63e71662fa4b2a2c3a26f570f037eb95bb1f85397f3cd8076caed2f026a6d100"
 dependencies = [
  "pin-project-lite",
+ "tracing-attributes",
  "tracing-core",
 ]
 
+[[package]]
+name = "tracing-attributes"
+version = "0.1.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7490cfa5ec963746568740651ac6781f701c9c5ea257c58e057f3ba8cf69e8da"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.118",
+]
+
 [[package]]
 name = "tracing-core"
 version = "0.1.36"

apps/desktop/src-tauri/Cargo.toml

@@ -33,6 +33,10 @@ tauri-plugin-http = "2"
 # (ws://127.0.0.1:3000 from the secure tauri://localhost origin) — HTTP and WS
 # are separate browser checks, so this needs its own plugin.
 tauri-plugin-websocket = "2"
+# Persists the operator-configured backend URL (host:port of the Fastify
+# server this install talks to) across restarts. Read before any API call —
+# see apps/web/src/lib/backend-config.ts.
+tauri-plugin-store = "2"
 
 [features]
 # Used by `tauri dev`/CLI for hot-reload of the Rust side.

apps/desktop/src-tauri/capabilities/default.json

@@ -8,11 +8,15 @@
     "updater:default",
     "process:default",
     "websocket:default",
+    "store:default",
     {
       "identifier": "http:default",
+      "//": "Backend address is operator-configured at runtime (backend-config.ts) so the exact host:port can't be allow-listed at build time. Wildcarded to any host — the CSP forces ALL backend traffic through this plugin (see tauri.conf.json), so this scope is the real boundary; a compromised/malicious page still can't reach anything the operator hasn't pointed the app at, since the app only ever calls the one configured origin. All 4 forms needed: a known Tauri scope-matching quirk drops http://*:PORT unless both bare and :* variants are listed.",
       "allow": [
-        { "url": "http://127.0.0.1:3000" },
-        { "url": "http://localhost:3000" }
+        { "url": "http://*" },
+        { "url": "https://*" },
+        { "url": "http://*:*" },
+        { "url": "https://*:*" }
       ]
     }
   ]

apps/desktop/src-tauri/src/lib.rs

@@ -3,9 +3,10 @@
 // Intentionally minimal: build the default Tauri app and run it. The window
 // config (kiosk, fullscreen, which URL/assets to load) lives in tauri.conf.json.
 // No custom commands are registered — the renderer (the @parking/web SPA) reaches
-// the backend over HTTP to the local Fastify server, NOT through Tauri IPC. This
-// keeps the shell a thin presentation wrapper with a deny-by-default native
-// surface (see wiki/decisions/desktop-shell-tauri.md).
+// the backend over HTTP to a Fastify server (address operator-configured at
+// runtime, not baked in — see apps/web/src/lib/backend-config.ts), NOT through
+// Tauri IPC. This keeps the shell a thin presentation wrapper with a
+// deny-by-default native surface (see wiki/decisions/desktop-shell-tauri.md).
 
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
@@ -16,13 +17,16 @@ pub fn run() {
         // endpoint + signing pubkey live in tauri.conf.json.
         .plugin(tauri_plugin_updater::Builder::new().build())
         .plugin(tauri_plugin_process::init())
-        // Routes the SPA's fetch()/WS calls to the local Fastify server through
-        // Tauri's native HTTP client — see the Cargo.toml comment on why the
-        // webview's own fetch() can't reach http://127.0.0.1:3000 directly.
+        // Routes the SPA's fetch()/WS calls to the operator-configured Fastify
+        // server through Tauri's native HTTP client — see the Cargo.toml
+        // comment on why the webview's own fetch() can't reach it directly.
         .plugin(tauri_plugin_http::init())
         // Live-feed WebSocket — same mixed-content reason as the HTTP plugin
         // above, but WS needs its own plugin (separate browser check).
         .plugin(tauri_plugin_websocket::init())
+        // Persists the operator-configured backend URL across restarts (JSON
+        // file in the app's config dir) — see backend-config.ts.
+        .plugin(tauri_plugin_store::Builder::new().build())
         .run(tauri::generate_context!())
         .expect("error while running the Parking System desktop shell");
 }

apps/desktop/src-tauri/tauri.conf.json

@@ -7,7 +7,7 @@
     "devUrl": "http://localhost:5173",
     "frontendDist": "../../web/dist",
     "beforeDevCommand": "pnpm --filter @parking/web dev",
-    "beforeBuildCommand": "VITE_API_BASE=http://127.0.0.1:3000 pnpm --filter @parking/web build"
+    "beforeBuildCommand": "pnpm --filter @parking/web build"
   },
   "app": {
     "windows": [
@@ -24,7 +24,7 @@
       }
     ],
     "security": {
-      "csp": "default-src 'self'; img-src 'self' data: blob:; style-src 'self' 'unsafe-inline'; connect-src 'self' http://127.0.0.1:3000 http://localhost:3000 ws://127.0.0.1:3000 ws://localhost:3000"
+      "csp": "default-src 'self'; img-src 'self' data: blob:; style-src 'self' 'unsafe-inline'; connect-src 'self'"
     }
   },
   "bundle": {