OTA: name release assets after their tag, download from one host

Two things the first live release check on git.wallacenet.ca showed:

- The publish script uploaded the APK under whatever the build called it
  (app-debug.apk), which is the name the updater only finds by its fallback
  rule. The script now names the asset after its tag, so the primary rule —
  "the asset whose name contains the tag" — is the one that fires.
- The instance answers for two host names and reports asset URLs on the one
  it treats as canonical, so the app would have fetched its release list from
  git.wallacenet.ca and its APK from elsewhere. onReportedHost() now keeps the
  path the server chose and puts the download on the host the app already
  trusts, tested in UpdatePolicyTest.

Co-Authored-By: Paperclip <[email protected]>

app/src/test/java/org/prolibertate/games/update/UpdatePolicyTest.kt

@@ -53,6 +53,28 @@ class UpdatePolicyTest {
         assertNull(versionCodeOfTag("nightly"))
     }
 
+    // -- Where the download happens ----------------------------------------
+
+    @Test
+    fun `a release asset is fetched from this app's host, keeping its path`() {
+        // The instance reports its canonical host; the app was told to trust
+        // another. Same bytes, one host, whatever the server names itself.
+        assertEquals(
+            "https://git.wallacenet.ca/devadmin/PilgrimsOfKatan/releases/download/" +
+                "v1.4.1001-dev/PilgrimsOfKatan-v1.4.1001-dev.apk",
+            onReportedHost(
+                "https://git.saskvalleytech.com/devadmin/PilgrimsOfKatan/releases/download/" +
+                    "v1.4.1001-dev/PilgrimsOfKatan-v1.4.1001-dev.apk",
+                "git.wallacenet.ca",
+            ),
+        )
+        // A URL that already says the right host is left exactly as it is.
+        val already = "https://git.wallacenet.ca/devadmin/PilgrimsOfKatan/releases/download/v1.4.1/a.apk"
+        assertEquals(already, onReportedHost(already, "git.wallacenet.ca"))
+        // Anything unparseable survives untouched rather than being dropped.
+        assertEquals("not a url", onReportedHost("not a url", "git.wallacenet.ca"))
+    }
+
     // -- The wall -----------------------------------------------------------
 
     @Test