Declare app version per channel and fix Android live updates

- Add channel.appVersion and an appPackage override so pure builds bake the pinned version instead of RadiantWave's 0.1.0 default.

- Pin the radiantwave input to tag 1.8 and allow unfree in the RPi builder to match x86.

- radiantwaveUpdaterModule gains a manifestFile arg; Raspberry Pi polls aarch64-manifest.json.

- Launch the rotated/Android kiosk through /var/lib/radiantwave/current so the live updater actually applies.

flake.lock

@@ -220,16 +220,16 @@
         "nixpkgs": "nixpkgs_3"
       },
       "locked": {
-        "lastModified": 1787675420,
-        "narHash": "sha256-2Hq9IcgdDXQc2uQ4yC/5NZVjcZaFCcVS78vj+ee+y/Q=",
-        "ref": "main",
-        "rev": "43cd93bbd7dde69c55c00a28c1691e1a192eda39",
-        "revCount": 47,
+        "lastModified": 1790803867,
+        "narHash": "sha256-HRGQQlmn/kCsZIq1wBMFaW6q1xfSvwPhUS5CpG1mm+Q=",
+        "ref": "refs/tags/1.8",
+        "rev": "34c72b51ddc3da8d46d994e787ffd1f8e8dda77c",
+        "revCount": 85,
         "type": "git",
         "url": "https://gitea.radiantwavetech.com/RadiantWaveTech/radiantwave.git"
       },
       "original": {
-        "ref": "main",
+        "ref": "refs/tags/1.8",
         "type": "git",
         "url": "https://gitea.radiantwavetech.com/RadiantWaveTech/radiantwave.git"
       }