feat(openwrt): add TollGate provision button and direct-download fallback

- OpenWrtGateway.vue: add "Install TollGate" button when not installed;
  tracks connected credentials for reuse in the provision call
- install.rs: fall back to wget download from GitHub releases when the
  package is not in any opkg feed (mips_24kc and other arches supported)
- openwrt.rs: provision-tollgate now falls back to saved router_config
  for credentials, matching the behaviour of get-status

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

core/openwrt/src/tollgate/install.rs

@@ -6,11 +6,50 @@ use crate::Router;
 /// The OpenWrt package name for the TollGate reference implementation.
 const TOLLGATE_PACKAGE: &str = "tollgate-module-basic-go";
 
-/// Install tollgate-module-basic-go via opkg.
+/// Direct-download fallback URLs by opkg architecture string.
+/// Used when the package is not in any configured feed.
+/// Source: https://github.com/OpenTollGate/tollgate-module-basic-go/releases/tag/v0.2.0
+fn ipk_url(arch: &str) -> Option<&'static str> {
+    match arch {
+        "mips_24kc"          => Some("https://github.com/OpenTollGate/tollgate-module-basic-go/releases/download/v0.2.0/mips_24kc.ipk"),
+        "mipsel_24kc"        => Some("https://github.com/OpenTollGate/tollgate-module-basic-go/releases/download/v0.2.0/mipsel_24kc.ipk"),
+        "aarch64_cortex-a53" => Some("https://github.com/OpenTollGate/tollgate-module-basic-go/releases/download/v0.2.0/aarch64_cortex-a53.ipk"),
+        "aarch64_cortex-a72" => Some("https://github.com/OpenTollGate/tollgate-module-basic-go/releases/download/v0.2.0/aarch64_cortex-a72.ipk"),
+        "arm_cortex-a7"      => Some("https://github.com/OpenTollGate/tollgate-module-basic-go/releases/download/v0.2.0/arm_cortex-a7.ipk"),
+        _ => None,
+    }
+}
+
+/// Install tollgate-module-basic-go.
 ///
+/// Tries opkg first (works if a custom feed is configured). Falls back to
+/// downloading the .ipk directly from GitHub releases if opkg can't find it.
 /// Caller is responsible for running `opkg_update` first.
 pub fn install_tollgate(router: &Router) -> Result<()> {
     info!("[{}] Installing {}", router.host, TOLLGATE_PACKAGE);
-    router.opkg_install(TOLLGATE_PACKAGE)?;
+
+    // Fast path: standard opkg install (or already installed).
+    if router.opkg_install(TOLLGATE_PACKAGE).is_ok() {
+        return Ok(());
+    }
+
+    // Package not in any feed — download the .ipk directly.
+    let arch = router
+        .run_ok("opkg print-architecture | grep -v 'all\\|noarch' | tail -1 | awk '{print $2}'")?;
+    let arch = arch.trim();
+
+    let url = ipk_url(arch).ok_or_else(|| {
+        anyhow::anyhow!(
+            "No pre-built TollGate package for architecture '{}'. \
+             Add a custom opkg feed or build from source.",
+            arch
+        )
+    })?;
+
+    info!("[{}] Downloading TollGate for {} from GitHub releases", router.host, arch);
+    router.run_ok(&format!("wget -O /tmp/tollgate.ipk '{}'", url))?;
+    router.run_ok("opkg install --force-depends /tmp/tollgate.ipk")?;
+    router.run_ok("rm -f /tmp/tollgate.ipk")?;
+
     Ok(())
 }