Add E2EE diagnostic logging for debugging call encryption

- Enable diag file for all builds (was DEBUG-only)
- Add native frame count + bad streak query methods (JNI)
- Add periodic E2EE-HEALTH log with enc/dec frame counts
- Reduce scan receivers spam (only log on state change)
- Log E2EE state on call connected
- Log when attachSender/attachReceiver skips due to missing key

app/src/main/cpp/rosetta_e2ee.cpp

@@ -531,6 +531,7 @@ public:
     }
 
     uint32_t KeyFingerprint() const { return key_fingerprint_; }
+    int FrameCount() const { return diag_count_.load(std::memory_order_relaxed); }
 
     /* ── RefCountInterface ─────────────────────────────────────── */
     void AddRef() const override {
@@ -724,6 +725,8 @@ public:
     }
 
     uint32_t KeyFingerprint() const { return key_fingerprint_; }
+    int FrameCount() const { return diag_count_.load(std::memory_order_relaxed); }
+    uint32_t BadStreak() const { return bad_audio_streak_.load(std::memory_order_relaxed); }
 
     /* ── RefCountInterface ─────────────────────────────────────── */
     void AddRef() const override {
@@ -1121,4 +1124,33 @@ Java_com_rosetta_messenger_network_XChaCha20E2EE_nativeCloseDiagFile(
     }
 }
 
+/* ── Query frame counts for health checks ────────────────────── */
+
+JNIEXPORT jint JNICALL
+Java_com_rosetta_messenger_network_XChaCha20E2EE_nativeGetEncryptorFrameCount(
+        JNIEnv *, jclass, jlong ptr)
+{
+    if (ptr == 0) return -1;
+    auto *enc = reinterpret_cast<XChaCha20Encryptor *>(ptr);
+    return enc->FrameCount();
+}
+
+JNIEXPORT jint JNICALL
+Java_com_rosetta_messenger_network_XChaCha20E2EE_nativeGetDecryptorFrameCount(
+        JNIEnv *, jclass, jlong ptr)
+{
+    if (ptr == 0) return -1;
+    auto *dec = reinterpret_cast<XChaCha20Decryptor *>(ptr);
+    return dec->FrameCount();
+}
+
+JNIEXPORT jint JNICALL
+Java_com_rosetta_messenger_network_XChaCha20E2EE_nativeGetDecryptorBadStreak(
+        JNIEnv *, jclass, jlong ptr)
+{
+    if (ptr == 0) return -1;
+    auto *dec = reinterpret_cast<XChaCha20Decryptor *>(ptr);
+    return dec->BadStreak();
+}
+
 } /* extern "C" */