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>

Cargo.lock

@@ -4378,6 +4378,7 @@ dependencies = [
  "rustls",
  "serde",
  "serde_json",
+ "sha2",
  "tokio",
  "toml",
  "tower-http",
@@ -4397,10 +4398,13 @@ version = "0.1.0"
 dependencies = [
  "async-trait",
  "bytes",
+ "ed25519-dalek",
+ "hkdf",
  "quinn",
  "rcgen",
  "rustls",
  "serde_json",
+ "sha2",
  "tokio",
  "tracing",
  "wzp-proto",