feat: codec selection in settings (Opus / Opus Low / Codec2)

- Settings UI: radio buttons for encode codec selection
- Persisted via SettingsRepository
- Passed through WzpEngine.startCall(profile=) → JNI → Rust CallStartConfig
- Decode always accepts all codecs (per-packet codec_id switch)
- 0 = Opus 24k (GOOD), 1 = Opus 6k (DEGRADED), 2 = Codec2 1.2k (CATASTROPHIC)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/wzp-android/src/jni_bridge.rs

@@ -85,6 +85,7 @@ pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeStartCall(
     seed_hex_j: JString,
     token_j: JString,
     alias_j: JString,
+    profile_j: jint,
 ) -> jint {
     let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
         let relay_addr: String = env.get_string(&relay_addr_j).map(|s| s.into()).unwrap_or_default();
@@ -110,7 +111,7 @@ pub unsafe extern "system" fn Java_com_wzp_engine_WzpEngine_nativeStartCall(
         }
 
         let config = CallStartConfig {
-            profile: QualityProfile::GOOD,
+            profile: profile_from_int(profile_j),
             relay_addr,
             room,
             auth_token: if token.is_empty() { Vec::new() } else { token.into_bytes() },