Fix transcription sample-rate handling

[kcfancher]

Fix for #703.

Adds an optional sampleRate parameter to the decodeAudioToFloat32() function. The caption transcriber passes in a value of 16000 to prepare audio in the format Whisper expects.

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Summary by CodeRabbit

• Bug Fixes
  • Standardized audio sample rate for transcription processing to improve consistency and reliability of audio decoding across the application.

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: d93d4858-2409-4007-8100-77042e96919f

📥 Commits

Reviewing files that changed from the base of the PR and between 26d523e and dad7e78.

📒 Files selected for processing (3)

• apps/web/src/components/editor/panels/assets/views/captions.tsx
• apps/web/src/constants/transcription-constants.ts
• apps/web/src/lib/media/audio.ts

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📝 Walkthrough

Walkthrough

These changes add explicit sample rate specification for audio transcription. A new constant defines the default transcription sample rate of 16000 Hz, and audio decoding functions are updated to accept and utilize this rate when preparing audio for transcription.

Changes

Cohort / File(s)	Summary
Sample Rate Configuration apps/web/src/constants/transcription-constants.ts	Added new exported constant DEFAULT_TRANSCRIPTION_SAMPLE_RATE = 16000 to define a standard audio sample rate for transcription operations.
Audio Decoding Integration apps/web/src/lib/media/audio.ts, apps/web/src/components/editor/panels/assets/views/captions.tsx	Updated decodeAudioToFloat32 function to accept optional sampleRate parameter; captions component now passes DEFAULT_TRANSCRIPTION_SAMPLE_RATE when decoding audio for transcription workflows.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Poem

🐰 A rabbit hops through audio streams so fine,
With sample rates all perfectly aligned,
Sixteen thousand times per second's beat,
The transcription magic is now complete!

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Fix transcription sample-rate handling' clearly and concisely summarizes the main change: adding sample-rate handling to the transcription functionality.
Description check	✅ Passed	The description includes the issue reference, a clear explanation of the change, and confirmation of bug-fix checklist items (issue opened, maintainer approval).

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