refactor: simplify PlatformLog actuals and convert remaining interpolated log calls to lambdas

- Extract private log() helper in JVM and iOS PlatformLog to reduce
  copy-paste branching
- Fix JVM formatter to be private and non-nullable
- Convert 60+ interpolated Log.w/e/i calls to lambda overloads,
  including hot-path Filter.kt toJson() and LocalCache event processing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

quartz/src/commonTest/kotlin/com/vitorpamplona/quartz/nip01Core/store/sqlite/LargeDBTests.kt

@@ -62,7 +62,7 @@ class LargeDBTests {
             try {
                 db.insert(event)
             } catch (e: SQLiteException) {
-                Log.w("LargeDBTests", "Error inserting event: ${e.message} for event: ${event.toJson()}")
+                Log.w("LargeDBTests") { "Error inserting event: ${e.message} for event: ${event.toJson()}" }
             }
         }
     }
@@ -73,7 +73,7 @@ class LargeDBTests {
             try {
                 db.insert(event)
             } catch (e: SQLiteException) {
-                Log.w("LargeDBTests", "Error inserting event: ${e.message} for event: ${event.toJson()}")
+                Log.w("LargeDBTests") { "Error inserting event: ${e.message} for event: ${event.toJson()}" }
             }
         }
     }