Task 215: Transcription page E2E tests

Status: DONE

Description

Added Playwright E2E tests for transcription pages — previously zero browser coverage.

Tests added (7)

• Transcription index page loads and lists episode links
• EP01 has Layer 0 script tab (active by default)
• EP01 has 4 tabs (Layer 0/2/2/3)
• EP02 has 3 tabs (no Layer 0 script)
• Tab switching shows correct panel and hides others
• Transcription tables contain dialogue data (10+ rows)
• No raw VTT timing syntax leaks into rendered text

Verification

• 112 Playwright E2E tests: ALL PASS
• 1776 TS unit tests: ALL PASS