perf(feeds): remember isSensitive and content warning reasons per note

These derivations iterate every tag and parse every iMeta, so running
them on each recomposition churns through feed scrolls. Cache them in
remember(note) alongside the other per-note derivations.

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/PictureDisplay.kt

@@ -67,9 +67,9 @@ fun PictureDisplay(
     nav: INav,
 ) {
     val event = (note.event as? PictureEvent) ?: return
-    val uri = note.toNostrUri()
+    val uri = remember(note) { note.toNostrUri() }
-    val isSensitive = event.isSensitiveOrNSFW()
+    val isSensitive = remember(note) { event.isSensitiveOrNSFW() }
-    val reasons = collectContentWarningReasons(event)
+    val reasons = remember(note) { collectContentWarningReasons(event) }
 
     val images by
         remember(note) {

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/types/VideoDisplay.kt

@@ -53,9 +53,9 @@ fun JustVideoDisplay(
     val event = (videoEvent as? Event) ?: return
 
     val imeta = videoEvent.imetaTags().getOrNull(0) ?: return
-    val isSensitive = event.isSensitiveOrNSFW()
+    val isSensitive = remember(note) { event.isSensitiveOrNSFW() }
-    val reasons = collectContentWarningReasons(event)
+    val reasons = remember(note) { collectContentWarningReasons(event) }
-    val isImage = imeta.mimeType?.startsWith("image/") == true || RichTextParser.isImageUrl(imeta.url)
+    val isImage = remember(note) { imeta.mimeType?.startsWith("image/") == true || RichTextParser.isImageUrl(imeta.url) }
 
     val content by
         remember(note) {

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/pictures/PictureCardCompose.kt

@@ -97,9 +97,9 @@ private fun PictureCardImage(
     backgroundColor: MutableState<Color>,
     accountViewModel: AccountViewModel,
 ) {
-    val uri = note.toNostrUri()
+    val uri = remember(note) { note.toNostrUri() }
-    val isSensitive = event.isSensitiveOrNSFW()
+    val isSensitive = remember(note) { event.isSensitiveOrNSFW() }
-    val reasons = collectContentWarningReasons(event)
+    val reasons = remember(note) { collectContentWarningReasons(event) }
 
     val images by
         remember(note) {

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/shorts/VideoCardCompose.kt

@@ -103,9 +103,9 @@ private fun VideoCardImage(
     val event = (event as? Event) ?: return
 
     val imeta = videoEvent.imetaTags().getOrNull(0) ?: return
-    val isSensitive = event.isSensitiveOrNSFW()
+    val isSensitive = remember(note) { event.isSensitiveOrNSFW() }
-    val reasons = collectContentWarningReasons(event)
+    val reasons = remember(note) { collectContentWarningReasons(event) }
-    val isImage = imeta.mimeType?.startsWith("image/") == true || RichTextParser.isImageUrl(imeta.url)
+    val isImage = remember(note) { imeta.mimeType?.startsWith("image/") == true || RichTextParser.isImageUrl(imeta.url) }
 
     val content by
         remember(note) {

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/video/FileHeaderCardCompose.kt

@@ -100,11 +100,11 @@ private fun FileHeaderCardImage(
 ) {
     val fullUrl = event.url() ?: return
 
-    val isSensitive = event.isSensitiveOrNSFW()
+    val isSensitive = remember(note) { event.isSensitiveOrNSFW() }
-    val reasons = collectContentWarningReasons(event)
+    val reasons = remember(note) { collectContentWarningReasons(event) }
-    val isImage = event.mimeType()?.startsWith("image/") == true || RichTextParser.isImageUrl(fullUrl)
+    val isImage = remember(note) { event.mimeType()?.startsWith("image/") == true || RichTextParser.isImageUrl(fullUrl) }
-    val blurHash = event.blurhash()
+    val blurHash = remember(note) { event.blurhash() }
-    val dimensions = event.dimensions()
+    val dimensions = remember(note) { event.dimensions() }
 
     val content by remember(note) {
         val hash = event.hash()