Roadmap: build a whale design system across the TUI

[Hmbown]

Summary

The repo already has a strong DeepSeek palette and whale theme, but the overall UX still feels like a collection of good parts instead of one coherent visual language. We should turn the whale aesthetic into a real TUI design system.

Scope

• Unify header, footer, transcript, thinking blocks, tool rows, compaction states, and status messaging under one whale-first visual system
• Define semantic color and copy rules for:
  • user messages
  • assistant answers
  • thinking
  • tool work
  • coherence/context refresh states
  • warnings/errors/success
• Make motion and redraw behavior feel calm and intentional instead of noisy
• Keep accessibility and contrast guardrails intact

Acceptance Criteria

• The interface feels recognizably DeepSeek/whale throughout, not just in the palette
• Thinking, tool work, and coherence states are visually distinct and easy to read
• Snapshot tests and palette audits are updated where needed
• The new visual rules are documented for future contributors

Starting Points

• crates/tui/src/palette.rs
• crates/tui/src/tui/
• crates/tui/src/tui/widgets/header.rs
• crates/tui/tests/palette_audit.rs

[Hmbown]

Closing as stale — these April 11 roadmap items predate the v0.4.x / v0.5.0 work and are being replaced by concrete, actionable issues (#28-#35). Will reopen specific items if/when they're picked up.