feat: adaptive quality engine + codec indicator UI

Wire AdaptiveQualityController into Android engine for auto codec
switching based on network quality reports. Add color-coded TX/RX
codec badges to the in-call screen showing active codecs and Auto mode.

- Recv task: ingest QualityReports, feed to controller, signal profile
  changes via AtomicU8 to send task
- Send task: check for pending profile switch at frame boundaries,
  update encoder/FEC/frame size
- Track peer codec from incoming packet headers
- Kotlin UI: codec badges (blue=studio, green=good, amber=degraded,
  red=catastrophic) with Auto tag
- Add .taskmaster to .gitignore

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

crates/wzp-android/src/stats.rs

@@ -59,6 +59,12 @@ pub struct CallStats {
     pub capture_overflows: u64,
     /// Current mic audio level (RMS of i16 samples, 0-32767).
     pub audio_level: u32,
+    /// Our current outgoing codec name (e.g. "Opus24k", "Codec2_1200").
+    pub current_codec: String,
+    /// Last seen incoming codec from other participants.
+    pub peer_codec: String,
+    /// Whether auto quality mode is active.
+    pub auto_mode: bool,
     /// Number of participants in the room (from last RoomUpdate).
     pub room_participant_count: u32,
     /// Participant list (fingerprint + optional alias) serialized as JSON array.