[HarleyCoops]

Adds the first exoplanet discovery story: seven explorable Three.js scenes and a completed 94-second, 720p Manim draft for TOI-4342. The reverse prerequisite tree teaches light and blocked area, orbital distance and timing, observer geometry, transit masking, phase folding and sector evidence. The 18.908-day signal remains an unconfirmed candidate.

Includes an immutable eumemic/exoplanets source snapshot and its MIT license, the Astra-authored saved scene, preview assets, production hashes and retained advisory assessments. Adds homepage/showcase entries and local regeneration commands that make zero model or API calls.

Validation:

• 330 offline tests passed on the latest main base.
• JavaScript syntax and numerical fidelity to the candidate fit and all eight sector measurements passed.
• Browser checks covered the scene controls, observer view, narrow belt, phase folding/masking and 360px framing.
• The final movie fully decoded: 94 seconds, 1280×720, 30 fps, 2,820 frames. Published source/movie hashes match the production record.

The film is a working draft. The final local edit fixes caption encoding and cleans the ending; it is marked not_reviewed without further model review. Original Astra/TypeSafe Jev feedback and remaining film clarity limits are documented. The interactive scenes provide larger explorations of observer geometry and phase folding.

[HarleyCoops]

Closed during repository branch cleanup. The commits stay available on this PR; use 'Restore branch' to reopen the work.