refactor(cache): move LargeSoftCache to commons/jvmAndroid, fix ICacheProvider types

- Move LargeSoftCache from amethyst/model to commons/jvmAndroid/model/cache
  so both Android and Desktop share the same WeakReference cache implementation
- Change ICacheProvider return types from Any? to proper types (User?, Note?)
  since these model classes already live in commons
- Remove unnecessary casts in ThreadAssembler, ChatNewMessageState, SearchBarState
- Improve LargeSoftCache.cleanUp() to use single-pass iterator (zero allocation)
- Update Android imports in LocalCache, LargeSoftCacheAddressExt, and test

Per Vitor's feedback on PR #1905: BoundedLargeCache evicts arbitrarily.
LargeSoftCache uses WeakReferences so GC respects the reference graph.

amethyst/src/main/java/com/vitorpamplona/amethyst/model/LargeSoftCacheAddressExt.kt

@@ -20,6 +20,7 @@
  */
 package com.vitorpamplona.amethyst.model
 
+import com.vitorpamplona.amethyst.commons.model.cache.LargeSoftCache
 import com.vitorpamplona.quartz.nip01Core.core.Address
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.utils.cache.CacheCollectors

amethyst/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt

@@ -25,6 +25,7 @@ import androidx.compose.runtime.Stable
 import com.vitorpamplona.amethyst.Amethyst
 import com.vitorpamplona.amethyst.commons.model.Channel
 import com.vitorpamplona.amethyst.commons.model.cache.ICacheProvider
+import com.vitorpamplona.amethyst.commons.model.cache.LargeSoftCache
 import com.vitorpamplona.amethyst.commons.model.emphChat.EphemeralChatChannel
 import com.vitorpamplona.amethyst.commons.model.nip28PublicChats.PublicChatChannel
 import com.vitorpamplona.amethyst.commons.model.nip53LiveActivities.LiveActivitiesChannel

amethyst/src/test/java/com/vitorpamplona/amethyst/model/LargeCacheAddressableFilterTest.kt

@@ -20,6 +20,7 @@
  */
 package com.vitorpamplona.amethyst.model
 
+import com.vitorpamplona.amethyst.commons.model.cache.LargeSoftCache
 import com.vitorpamplona.quartz.nip01Core.core.Address
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import junit.framework.TestCase.assertEquals

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/ThreadAssembler.kt

@@ -52,7 +52,7 @@ class ThreadAssembler(
                 ?.getOrNull(1)
         if (markedAsRoot != null) {
             // Check to see if there is an error in the tag and the root has replies
-            val rootNote = cache.getNoteIfExists(markedAsRoot) as? Note
+            val rootNote = cache.getNoteIfExists(markedAsRoot)
             if (rootNote?.replyTo?.isEmpty() == true) {
                 return cache.checkGetOrCreateNote(markedAsRoot)
             }

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/cache/ICacheProvider.kt

@@ -57,7 +57,7 @@ interface ICacheProvider {
      * @param pubkey The user's public key in hex format
      * @return The User if exists in cache, null otherwise
      */
-    fun getUserIfExists(pubkey: HexKey): Any?
+    fun getUserIfExists(pubkey: HexKey): User?
 
     /**
      * Counts users matching a predicate.
@@ -75,7 +75,7 @@ interface ICacheProvider {
      * @param hexKey The note's ID in hex format
      * @return The Note if exists in cache, null otherwise
      */
-    fun getNoteIfExists(hexKey: HexKey): Any?
+    fun getNoteIfExists(hexKey: HexKey): Note?
 
     /**
      * Gets an existing Note or creates a new one if it doesn't exist.
@@ -123,7 +123,7 @@ interface ICacheProvider {
     fun findUsersStartingWith(
         prefix: String,
         limit: Int = 50,
-    ): List<Any> = emptyList()
+    ): List<User> = emptyList()
 
     /**
      * Gets or creates a User by public key hex.
@@ -132,7 +132,7 @@ interface ICacheProvider {
      * @param pubkey The user's public key in hex format
      * @return The User (existing or newly created)
      */
-    fun getOrCreateUser(pubkey: HexKey): Any?
+    fun getOrCreateUser(pubkey: HexKey): User?
 
     fun justConsumeMyOwnEvent(event: Event): Boolean
 }

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/viewmodels/ChatNewMessageState.kt

@@ -24,7 +24,6 @@ import androidx.compose.runtime.Stable
 import androidx.compose.ui.text.input.TextFieldValue
 import com.vitorpamplona.amethyst.commons.model.IAccount
 import com.vitorpamplona.amethyst.commons.model.Note
-import com.vitorpamplona.amethyst.commons.model.User
 import com.vitorpamplona.amethyst.commons.model.cache.ICacheProvider
 import com.vitorpamplona.quartz.nip01Core.tags.hashtags.hashtags
 import com.vitorpamplona.quartz.nip01Core.tags.references.references
@@ -95,7 +94,7 @@ class ChatNewMessageState(
         if (currentRoom != null) {
             _recipientsMissingDmRelays.value =
                 currentRoom.users.any { hexKey ->
-                    val user = cache.getOrCreateUser(hexKey) as? User
+                    val user = cache.getOrCreateUser(hexKey)
                     user?.dmInboxRelays().isNullOrEmpty()
                 }
         } else {
@@ -141,7 +140,7 @@ class ChatNewMessageState(
     ) {
         val pTags =
             room.users.mapNotNull { hexKey ->
-                (cache.getOrCreateUser(hexKey) as? User)?.toPTag()
+                cache.getOrCreateUser(hexKey)?.toPTag()
             }
 
         val replyHint = _replyTo.value?.toEventHint<BaseDMGroupEvent>()

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/viewmodels/SearchBarState.kt

@@ -88,8 +88,7 @@ class SearchBarState(
             .debounce(debounceMs)
             .onEach { query ->
                 if (query.length >= 2 && _bech32Results.value.isEmpty()) {
-                    @Suppress("UNCHECKED_CAST")
-                    _cachedUserResults.value = cache.findUsersStartingWith(query, 20) as List<User>
+                    _cachedUserResults.value = cache.findUsersStartingWith(query, 20)
                 } else {
                     _cachedUserResults.value = emptyList()
                 }

commons/src/jvmAndroid/kotlin/com/vitorpamplona/amethyst/commons/model/cache/LargeSoftCache.kt

@@ -18,7 +18,7 @@
  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-package com.vitorpamplona.amethyst.model
+package com.vitorpamplona.amethyst.commons.model.cache
 
 import com.vitorpamplona.quartz.utils.cache.CacheOperations
 import java.lang.ref.WeakReference
@@ -59,7 +59,7 @@ class LargeSoftCache<K : Any, V : Any> : CacheOperations<K, V> {
 
     /**
      * Puts an object into the cache with a specified key.
-     * The object is stored as a SoftReference.
+     * The object is stored as a WeakReference.
      *
      * @param key The key to associate with the object.
      * @param value The object to cache.
@@ -105,19 +105,16 @@ class LargeSoftCache<K : Any, V : Any> : CacheOperations<K, V> {
 
     /**
      * Proactively cleans up the cache by removing entries whose weakly referenced
-     * objects have been garbage collected. While `get` handles cleanup on access,
-     * this method can be called periodically or when memory pressure is high.
+     * objects have been garbage collected. Single-pass iterator for efficiency.
      */
     fun cleanUp() {
-        val keysToRemove = mutableMapOf<K, WeakReference<V>>()
-        cache.forEach { key, softRef ->
-            if (softRef.get() == null) {
-                keysToRemove.put(key, softRef)
+        val iter = cache.entries.iterator()
+        while (iter.hasNext()) {
+            val entry = iter.next()
+            if (entry.value.get() == null) {
+                iter.remove()
             }
         }
-        keysToRemove.forEach { key, value ->
-            cache.remove(key, value)
-        }
     }
 
     override fun forEach(consumer: BiConsumer<K, V>) {