Task 552: Timeline analysis test expansion

Status: DONE

Summary

Added 10 tests to timeline-analysis.test.ts (20→30):

FIXED_DURATIONS (new, 0→3)

1. EP01 is 72h = 3 days
2. EP03 is ~143h ≈ 5.96 days
3. EP05 coast is 375h ≈ 15.6 days

searchMultipleEpochs (new, 0→3)

1. Returns multiple candidate timelines
2. All results have 4 events
3. Results are sorted by total duration

ep02SensitivityAnalysis (new, 0→2)

1. Returns multiple scenarios
2. Each scenario has positive transit time

narrativePlausibilityAnalysis (new, 0→2)

1. Returns entries for multiple episodes
2. Each entry has reasoning and coastFeelsLong boolean

Impact

• Stats: 4,007 TS, 531 Rust, 265 E2E (4,803 total)
• All 6 exported functions from timeline-analysis.ts now tested