Add transcript timestamps and download

[mcminis1]

Changes

• Added "Download" button to export conversation transcript as CSV
• Added timestamps display for each message in transcript
• CSV includes timestamp, participant role (Agent/User), and message text
• Updated transcript UI to show timestamps below each message
• Fixed message merging logic to preserve original timestamps

Implementation Details

• CSV export handles quote escaping and uses ISO date for filename
• Timestamps use 24-hour format with HH:mm:ss
• Preserved backward compatibility by making timestamp optional in Transcription interface
• Enhanced message merge logic to maintain chronological accuracy

Testing

• Verify CSV download contains all messages with correct timestamps
• Confirm timestamps display correctly in UI
• Test message merging with multiple rapid messages
• Validate CSV formatting with messages containing quotes/special chars

Chat Transcript

Chat CSV

[mcminis1]

@bcherry I built this for myself and thought it might be something other folks would like. Glad to take a turn on it if it's something you're interested in merging, but not quite the way you like it.

Thanks!