Add dev/production update channels, clearer Euchre table, bolder Sequence highlight

Update channels
- ci.yml now publishes each green push to dev as a prerelease tagged
  v1.0.<n>-dev, so the dev channel has something to install. Workflow
  artifacts could not serve this: downloading one needs authentication,
  which the app does not have.
- Prereleases specifically, because GitHub's "latest release" endpoint
  skips them — a production install can never be handed a dev build.
  Pull requests build and check but never publish.
- Settings gains a channel picker. The two channels are numbered by
  separate workflow run counters, so versions are only compared within a
  channel; the app reads the -dev suffix in its own versionName to know
  where it stands, and treats a channel change as an explicit switch. The
  screen warns that such a switch can be a downgrade Android will refuse.
- PLG_RELEASE becomes PLG_CHANNEL, naming the channel rather than a flag.

Euchre
- Cards in a trick now sit on the side of the table belonging to whoever
  played them, rotated to face them, labelled You / Left / Partner /
  Right. Previously they were a flat row tagged with seat numbers, which
  made it hard to tell who had played what.
- Bidding says what it will actually do. As dealer the button reads "Pick
  it up" rather than "Order up", since the turn card comes to your hand,
  and a line of explanatory text spells out the consequence either way.

Sequence
- Playable squares get a much heavier outline, scaled off cell size and
  in a fixed amber that reads against a white card, a green corner and a
  chip alike. The old 2dp theme-coloured border was hard to see.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015qjfMiPUDshdKEUa6vxqzN

app/build.gradle.kts

@@ -4,20 +4,17 @@ plugins {
     id("org.jetbrains.kotlin.plugin.serialization")
 }
 
-// Only the release workflow stamps a real version. It sets PLG_RELEASE, and its
-// GITHUB_RUN_NUMBER is the same number as the release tag it publishes
-// (v1.0.<run-number>), so the shipped APK knows its own version and the in-app
-// updater can compare against the latest published release.
+// Which update channel this build belongs to, set by whichever workflow built
+// it: release.yml stamps "production" from main, ci.yml stamps "dev" from the
+// dev branch. Unset for a local build, which counts as dev.
 //
-// Everything else — a local build, or the dev CI pipeline — stays at 1.0.0-dev.
-// GITHUB_RUN_NUMBER alone is NOT enough to key off: it counts per workflow, so
-// the dev pipeline has its own independent sequence. A debug APK installed from
-// a CI artifact would otherwise carry that counter as its versionCode, could
-// outrank a genuine release, and would leave the updater reporting "you're on
-// the latest version" indefinitely.
-val isReleaseBuild = System.getenv("PLG_RELEASE") == "1"
-val releaseRunNumber = (System.getenv("GITHUB_RUN_NUMBER") ?: "").toIntOrNull() ?: 0
-val stampReleaseVersion = isReleaseBuild && releaseRunNumber > 0
+// GITHUB_RUN_NUMBER alone is not enough to key off, because it counts per
+// workflow — the two pipelines have entirely independent sequences. That is
+// also why versionCode is only ever compared *within* a channel; see
+// UpdateChannel for how switching between them is handled.
+val buildChannel = System.getenv("PLG_CHANNEL").orEmpty()
+val runNumber = (System.getenv("GITHUB_RUN_NUMBER") ?: "").toIntOrNull() ?: 0
+val stampVersion = buildChannel.isNotEmpty() && runNumber > 0
 
 android {
     namespace = "org.prolibertate.games"
@@ -27,12 +24,14 @@ android {
         applicationId = "org.prolibertate.games"
         minSdk = 24
         targetSdk = 34
-        // Dev builds sit at 1, below every release except the very first —
-        // a v1.0.1 release ties with a dev build and so is not offered as an
-        // update. Harmless, and preferable to versionCode 0, which Android
-        // documents as out of range.
-        versionCode = if (stampReleaseVersion) releaseRunNumber else 1
-        versionName = if (stampReleaseVersion) "1.0.$releaseRunNumber" else "1.0.0-dev"
+        // The -dev suffix in versionName is what the installed app reads to
+        // know its own channel, so it must survive into the shipped APK.
+        versionCode = if (stampVersion) runNumber else 1
+        versionName = when {
+            stampVersion && buildChannel == "production" -> "1.0.$runNumber"
+            stampVersion -> "1.0.$runNumber-dev"
+            else -> "1.0.0-dev"
+        }
     }
 
     signingConfigs {