fix(bin): preserve complete hold-to-speak recordings

[Amplify-Logic]

Intent

Fix the urgent field bug on the Starship bridge hold-to-speak control: the captain held the button and spoke full sentences, but the uploaded m4a files were 784 bytes and 11 KB (only the final instant of speech; transcripts "Bye." and "you"). A captain-side Sent must mean the entire press-to-release recording left the phone, not the last MediaRecorder chunk.

Required outcome:

• Collect every dataavailable chunk into an array, build the blob in onstop after the last flush, then POST so the entire audio from press to release is one file.
• Keep the PR feat: upgrade the captain bridge with photos and hold-to-speak #90 race protection: release during getUserMedia must still cancel cleanly with no infinite recording.
• Client-side sanity guard: if the built blob is smaller than about 1KB per second held (with a floor), show the failure state instead of claiming Sent.
• Server side: log received audio byte size per /speak request in the bridge log so field truncation is visible.
• Tests: extend existing bridge tests for the upload path (full-blob assembly via unit-testable page JS; server-side size logging). Do not fake browser tests that prove nothing.
• iPhone Safari is the only client that matters (audio/mp4). Do not restart or repoint launchd services.
• Existing bridge behavior from feat: upgrade the captain bridge with photos and hold-to-speak #90/fix(bin): calm the phone glance with focused work groups #91 stays unchanged except this capture-integrity fix.

What Changed

• Accumulate every iPhone Safari MediaRecorder timeslice and final flush into one audio file before uploading.
• Reject undersized recordings client-side and log extracted audio byte counts for /speak requests.
• Extend bridge tests and documentation for full-chunk assembly, truncation detection, and server-side size logging.

Risk Assessment

✅ Low: The change is well-bounded, satisfies the capture-integrity requirements, preserves the early-release race protection, and introduces no material issues found in review.

Testing

The full bridge suite passed, covering the #90 release-during-permission race, complete Safari m4a blob assembly, undersized-capture rejection, the real /speak forwarding path, and server byte-size logging. Focused evidence shows a 6,500-byte full capture reaching “Sent” while a 784-byte capture is rejected without POSTing. No screenshot was captured because meaningful verification requires iPhone Safari MediaRecorder events; a static rendered page would not demonstrate capture integrity.

Evidence: Capture-integrity end-user transcript

A 3-second press assembled all chunks into one 6,500-byte audio/mp4 upload and displayed “Sent”. An undersized 8-second capture displayed “Recording was too small to send.” and made no POST.

{
  "full_press_3s": {
    "listening": {
      "status": "Listening…",
      "button": "Release to send",
      "timeslice_ms": 1000
    },
    "final": {
      "status": "Sent",
      "state": "ok"
    },
    "final_flush_requested": true,
    "tracks_stopped": true,
    "posts": [
      {
        "field": "audio",
        "filename": "bridge.m4a",
        "bytes": 6500,
        "type": "audio/mp4"
      }
    ]
  },
  "truncated_press_8s": {
    "listening": {
      "status": "Listening…",
      "button": "Release to send",
      "timeslice_ms": 1000
    },
    "final": {
      "status": "Recording was too small to send.",
      "state": "warn"
    },
    "final_flush_requested": true,
    "tracks_stopped": true,
    "posts": []
  }
}

Pipeline

Updates from git push no-mistakes

✅ **intent** - passed

✅ No issues found.

✅ **Rebase** - passed

✅ No issues found.

✅ **Review** - passed

✅ No issues found.

✅ **Test** - passed

✅ No issues found.

• Inspected git diff --unified=80 3418df5656d8dc5a613319525b68a1a7e3cbf3c1..57edb04c3a54f1f29fde54c8f2ccf94a9ba11e7c against the authoritative intent
• bash tests/fm-bridge-view.test.sh
• Executed the actual PAGE_JS in a MediaRecorder harness simulating Safari timeslice chunks, final flush ordering, a valid 3-second capture, and a truncated 8-second capture; saved the resulting user-visible state and upload transcript
• git status --short && git diff --exit-code

✅ **Document** - passed

✅ No issues found.

✅ **Lint** - passed

✅ No issues found.

✅ **Push** - passed

✅ No issues found.