fix: reorder pruning tiers in MemoryTrimmingService

Tier 2 (medium, >= RUNNING_LOW): pruneHiddenEvents + pruneHiddenMessages
  — muted/blocked content is known-safe to drop at low pressure.

Tier 3 (critical, >= RUNNING_CRITICAL): pruneOldMessages + pruneRepliesAndReactions
  — these are more aggressive since they remove content the user may
  still scroll back to, so reserve them for genuine memory emergencies.

Co-Authored-By: Claude <noreply@anthropic.com>

amethyst/src/main/java/com/vitorpamplona/amethyst/service/eventCache/MemoryTrimmingService.kt

@@ -61,19 +61,19 @@ class MemoryTrimmingService(
         cache.prunePastVersionsOfReplaceables()
 
         if (level >= ComponentCallbacks2.TRIM_MEMORY_RUNNING_LOW) {
-            // Tier 2: medium pressure — drop messages and unobserved reactions
-            val accounts = otherAccounts.mapNotNull { decodePublicKeyAsHexOrNull(it.npub) }.toSet()
-            cache.pruneOldMessages()
-            cache.pruneRepliesAndReactions(accounts)
-        }
-
-        if (level >= ComponentCallbacks2.TRIM_MEMORY_RUNNING_CRITICAL) {
-            // Tier 3: critical pressure — drop muted content
+            // Tier 2: medium pressure — drop events from muted/blocked users
             account.forEach {
                 cache.pruneHiddenEvents(it)
                 cache.pruneHiddenMessages(it)
             }
         }
+
+        if (level >= ComponentCallbacks2.TRIM_MEMORY_RUNNING_CRITICAL) {
+            // Tier 3: critical pressure — drop old messages and unobserved reactions
+            val accounts = otherAccounts.mapNotNull { decodePublicKeyAsHexOrNull(it.npub) }.toSet()
+            cache.pruneOldMessages()
+            cache.pruneRepliesAndReactions(accounts)
+        }
     }
 
     suspend fun run(