Compose Multiplatform 1.12.0

The last four lint warnings were all this one thing, and they were right:
1.11.1 with 1.12.0 out. Nothing else here is behind -- material3 1.9.0 and
activity-compose 1.13.0 are both current, checked against Maven Central and
Google Maven today, which is also why the header comment's date moves.

Android Lint now reports no issues at all, from 11 errors and 8 warnings
this morning.

Verified by running it rather than by the build succeeding, since a Compose
minor can change how things draw: the session list, the usage screen and a
session transcript with a message sent through it all render as before.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017xn8nHw1tw1R6PtiY1eEtw

app/gradle/libs.versions.toml

@@ -1,10 +1,10 @@
-# Latest stable versions as of 2026-08-24 (checked against Google Maven /
+# Latest stable versions as of 2026-08-28 (checked against Google Maven /
 # Maven Central; prereleases deliberately skipped). zxing-embedded checked
 # 2026-08-25.
 [versions]
 agp = "9.3.2"
 kotlin = "2.4.10"
-compose-multiplatform = "1.11.1"
+compose-multiplatform = "1.12.0"
 # material3 ships on its own release train, separate from the CMP version.
 compose-material3 = "1.9.0"
 androidx-activityCompose = "1.13.0"