ui: improve Compose stability and message UI

- Add minute/second abbreviations and kotlin.time-based relative time formatter
- Introduce FastPreview and update previews to use AppTheme with dark/dynamic colors
- Refactor attachments preview grid & waveform to use ImmutableList and reduce recompositions
- Tweak message bubble reply styling and swipe-to-reply animation/haptics
- Add Compose Stability Analyzer plugin and enable it in debug builds
- Cache shared images by sha256 and improve share intent/chooser text
- Minor UX polish (e.g., “No views”) and immutability annotations

build-logic/convention/src/main/kotlin/AndroidLibraryComposeConventionPlugin.kt

@@ -10,6 +10,7 @@ class AndroidLibraryComposeConventionPlugin : Plugin<Project> {
         with(target) {
             apply(plugin = "com.android.library")
             apply(plugin = "org.jetbrains.kotlin.plugin.compose")
+            apply(plugin = "com.github.skydoves.compose.stability.analyzer")
 
             val extension = extensions.getByType<LibraryExtension>()
             extension.androidResources.enable = false