Prepare the 0.3.8 release (#187)

## What's in it

- `scripts/release.sh prepare --version 0.3.8`: workspace version, the 44
  internal dependency pins, both lockfiles, and the three active release
  metadata files.
- The hand sweep prepare doesn't reach, matching 0.3.7's `228a4aff`: 14
  example manifests + `examples/Cargo.lock`, ten crate READMEs, the
  rvoip-sip docs set, `docs/RELEASING.md`, and the workflow's version hint.
  Two references deliberately stay at 0.3.7: `check_public_api.sh`'s
  semver baseline (the *previous* release is the comparison target) and
  the OpenSIPS TLS provenance note (a historical statement).
- CHANGELOG `0.3.8` entry and a rewritten `RELEASE_NOTES_NEXT.md`,
  including an **Upgrading from 0.3.7** section: the one source-level
  change for downstream code is `CodecInfo` literals adding
  `payload_type: None`. Every other consumer-constructed type
  (`MediaFrame`, `SymmetricRtpPolicy`, `SipTraceConfig`, `MediaMode`) was
  diffed against `v0.3.7` and is shape-identical.
- A pre-publish API review moved the three new AMR knobs off `Config`'s
  public fields onto `with_amr_dtx` / `with_amr_auto_cmr` /
  `with_amr_mode_set` builders (private fields — the constructible shape
  stays frozen at 0.3.7's). Fifteen in-repo functional-record-update
  construction sites were converted to the documented constructors.
  `cargo semver-checks` vs `v0.3.7`: **no semver update required**.
- Example 12 fixed for the `CodecInfo` field addition (it had never
  compiled since the field landed; only main-ci builds all 14 examples).

## Issue triage folded in

All ten bug-shaped open issues were evaluated against this branch:
#176 is fixed by this release (closed); #163, #166, #167 were fixed in
0.3.7 and are now closed against their evidence; #177 and #170 updated
as partially addressed; #169, #168, #86, #164 confirmed valid and open;
follow-ups #184, #185, #186 filed from the verification residuals.

None of the open issues is a 0.3.8 regression; nothing new rides this
release beyond the API-shape corrections above.

## After merge

`remote-preflight`, then `remote-release` qualification with
`first_candidate=true` — the gate catalog changed (+17 gates), so the
catalog hash is fresh and no prior evidence reuses. Publish follows the
protected workflow. Bridgefu's pin bump has a prepared 7-site patch.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Author: eisenzopf

.github/workflows/release-prepare.yml

@@ -4,7 +4,7 @@ on:
   workflow_dispatch:
     inputs:
       version:
-        description: Stable SemVer without a leading v (for example 0.3.7)
+        description: Stable SemVer without a leading v (for example 0.3.8)
         required: true
         type: string
 

CHANGELOG.md

@@ -2,6 +2,71 @@
 
 ## Unreleased
 
+## 0.3.8 — 2026-08-14
+
+This coordinated 44-crate patch release brings AMR-NB and AMR-WB into the
+codec set end to end — negotiation, transport, transcoding, and release
+evidence — adds record-routed proxy interop to the qualification matrix, and
+repairs SIPS dialog and opus-bridge edge cases found on the way.
+
+### AMR codecs
+
+- Add AMR-NB and AMR-WB with IF1 and IF2 interface formats, VAD1/VAD2 and DTX
+  reaching the wire, receive-side interleaving reassembly, max-red redundancy
+  scheduling with dedup, and CMR damping — bit-exact against the fetched
+  TS 26.073/26.101/26.201 material, with no 3GPP sources in the repository.
+- Negotiate and obey the SDP mode-set, prove every mode in a live call, and
+  attest each rate in the release evidence; long-run soaks cover both
+  variants.
+- Admit dynamic codecs into the media graph by their negotiated payload type
+  (`CodecInfo` now carries it), re-frame packet times AMR cannot accept
+  (10 ms joins and 30 ms splits), and label emitted frames so the UCTP pumps
+  stop stamping Opus's number on everything else.
+- Prove AMR crosses SRTP in process and a QUIC datagram in both directions.
+
+### SIP, proxies, and interop
+
+- Generate a secure fallback Contact for every RFC 3261 §12.1.1 trigger, so
+  secure dialogs answer with `sips:` at the TLS-advertised address while
+  explicit Contact and plain-SIP behavior are preserved (issue #176). This
+  also repairs rvoip-to-rvoip SIPS setup: `Dialog::from_2xx_response` refuses
+  a secure dialog whose Contact is not `sips:`, which the old plain fallback
+  tripped.
+- Learn the UAC route set from the dialog-forming 2xx's Record-Route
+  (reversed per §12.1.2), so in-dialog requests stop bypassing
+  record-routing proxies; the UAS side reads it from the request.
+- Add Kamailio and OpenSIPS registrar-proxy labs with TLS and SRTP through
+  rtpengine, opt-in AMR-NB transcoding (the AMR-WB transcode failure is
+  attributed to rtpengine), and a per-rate sweep bound to the gate catalog.
+- Expose the profiled egress registration's coordinator for
+  observation-only event subscriptions; the composite adapter remains the
+  sole signaling and lifecycle owner.
+- `Config` gains `with_amr_dtx`, `with_amr_auto_cmr`, and
+  `with_amr_mode_set` builders (private fields — `Config`'s constructible
+  shape stays frozen). DTX and auto-CMR are local media policy; only the
+  RFC 4867 `mode-set` is negotiated.
+- `CodecInfo` carries the payload type a transport negotiated
+  (`payload_type: Option<u8>`). Code constructing `CodecInfo` literals adds
+  one field on upgrade; `None` preserves the name-table behavior.
+
+### Media graph and bridges
+
+- Keep opus↔opus bridges passthrough when the two legs numbered opus
+  differently: the payload type is a per-leg SDP artifact, so the bypass
+  compares name, rate, and channels, and passthrough restamps the sink's
+  payload type on egress.
+- Make a barge-in flush empty the re-framing accumulator as well as the sink
+  queues, so no pre-interruption audio or dead-timeline timestamp survives
+  into the first post-flush frame.
+- Reach the opus and all-codecs feature sets from the rvoip facade.
+
+### Qualification
+
+`0.3.8` requires a fresh `remote-release` qualification bound to the updated
+gate catalog, which adds the AMR per-rate sweep, the proxy-PBX media family,
+and the AMR fuzz targets. Because the aggregate is bound to the catalog hash,
+no `0.3.7` evidence qualifies this release.
+
 ## 0.3.7 — 2026-08-06
 
 This coordinated 44-crate patch release hardens voice-AI and WebRTC media under