[codex] fix recorder codec handling and bridge re-INVITE selection

[yeoleobun]

What changed

This branch contains two local commits that are ahead of upstream/main:

• fix recorder handling for dynamic codec/PT updates and DTMF paths
• fix bridge-backed re-INVITE answer generation so bridged WebRTC/RTP calls use the correct local PeerConnection during in-dialog renegotiation

Why

The re-INVITE fix addresses a WebRTC/RTP bridge failure where SIP session renegotiation looked only at caller/callee media peers for a local PeerConnection, even when the active transport conversion state lived on media_bridge. That caused bridge-backed re-INVITEs to fail to build a local answer.

Impact

• bridge-backed re-INVITEs can now resolve the correct local PeerConnection
• the regression is covered by a focused SipSession unit test
• recorder-path updates from the prior local commit are included because they are also ahead of upstream/main on this branch

Validation

• cargo test test_get_local_reinvite_pc_uses_bridge_when_present --lib