chore(deps): split androidx-compose version ref from CMP

The compose-multiplatform version ref in libs.versions.toml was shared
between the org.jetbrains.compose.* artifacts (plus Gradle plugin) and
the two androidx.compose.{runtime,ui} test/tracing artifacts. Google
ships the androidx side first; when Renovate noticed androidx
1.11.0-rc01 it bumped the shared variable and the build choked because
JetBrains had not yet published the org.jetbrains.compose plugin at
that version (see PR #5180).

Introduce a dedicated androidx-compose-bom-aligned version ref for the
two androidx artifacts so Renovate can bump them without dragging CMP,
and add a Renovate group rule that keeps both ecosystems updated
together so they stay aligned in practice. AndroidCompose.kt's
resolutionStrategy continues to force these groups to the CMP version
at resolution time, so runtime behavior is unchanged.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

.github/renovate.json

@@ -56,6 +56,15 @@
       "changelogUrl": "https://github.com/meshtastic/protobufs/compare/{{currentDigest}}...{{newDigest}}",
       "automerge": true
     },
+    {
+      "description": "Group CMP and the androidx.compose artifacts that track it so Renovate bumps them together (see PR #5180)",
+      "groupName": "compose-multiplatform",
+      "matchPackageNames": [
+        "/^org\\.jetbrains\\.compose/",
+        "androidx.compose.runtime:runtime-tracing",
+        "androidx.compose.ui:ui-test-manifest"
+      ]
+    },
     {
       "description": "Restrict sensitive infrastructure to manual minor updates",
       "matchUpdateTypes": [