Refine WonderDrive research journey experience

[Mister-JP]

What changed

• Reworked the WonderDrive journey into a stable editorial answer card with compact typography, integrated factual media, in-place buffering skeletons, and exactly two next-direction choices.
• Added a closable deeper-dive overlay for full answer details, sources, research activity, cost, model, and metadata.
• Removed the separate research-steps loading page and the redundant highlighted conclusion block.
• Consolidated client API handling and hardened route, repository, validation, citation, and error boundaries.
• Added starter recommendations, replacement-question research, the corresponding D1 migration, architecture index, and design artifacts.

Why

The experience should feel like reading a concise, trustworthy researched article that naturally leads into the next curiosity choice, without disruptive loading transitions or competing dashboard panels.

Impact

Users keep their question and journey context visible throughout research, receive a denser sourced answer with optional imagery, and can inspect full evidence without leaving the main journey screen.

Validation

• Production build
• Architecture check
• ESLint
• TypeScript check
• Rendered shell and health contract tests
• Fixture invariants
• Live research normalization, citation, repair, and context tests