feat(trunk): G711Codec — µ-law encode/decode + 8kHz↔24kHz linear-interpolated resampling (slice-5 T1)

In-core ~30-line table-driven codec (no dep). The ITU-T G.711 µ-law
companding formula is a piece of telephony history worth teaching (AGENTS.md
learner-facing comment mandate). 3× linear upsample on decode; 3× decimation
downsample on encode. The resampler artifacts are below the barge-in trigger
threshold (LocalVadReflex only needs RMS energy); rubato lands in a post-
spearhead refinement if a downstream consumer needs better (spec §6.6).

Task T1 of slice-5 — T3 (TwilioMediaStreamsServer) consumes this codec.

Signed-off-by: Aaron D. Lee <himself@adlee.work>

Cargo.lock

@@ -143,6 +143,7 @@ dependencies = [
  "async-trait",
  "axum-core",
  "axum-macros",
+ "base64",
  "bytes",
  "futures-util",
  "http",
@@ -161,8 +162,10 @@ dependencies = [
  "serde_json",
  "serde_path_to_error",
  "serde_urlencoded",
+ "sha1",
  "sync_wrapper",
  "tokio",
+ "tokio-tungstenite",
  "tower",
  "tower-layer",
  "tower-service",
@@ -1280,6 +1283,20 @@ dependencies = [
 [[package]]
 name = "rutster-trunk"
 version = "0.0.0"
+dependencies = [
+ "axum",
+ "base64",
+ "rutster-call-model",
+ "rutster-media",
+ "rutster-tap",
+ "serde",
+ "serde_json",
+ "thiserror 1.0.69",
+ "tokio",
+ "tower",
+ "tracing",
+ "url",
+]
 
 [[package]]
 name = "ryu"