style: unified frosted glass aesthetic for AskBarView and ConversationView

[quiet-node]

Summary

• Applies the warm ambient aesthetic from the approved onboarding screens to the main chat UI
• All changes are CSS-only in App.css — no layout, animation, or component logic touched
• Brings visual consistency between the onboarding flow and the core AskBarView + ConversationView

Changes

• Warm surface tokens: base surface shifted from neutral rgba(26,26,28) to warm dark rgba(22,18,15,0.98), matching onboarding panel warmth
• Radial gradient glow: top of morphing container now has the signature warm orange radial gradient (ellipse 70% 40% at 50% 0%) present in both approved onboarding screens
• Top border accent: border-top-color: rgba(255,141,92,0.2) + ::before glowing line pseudo-element at the top edge
• AI chat bubble: warmed from neutral gray rgba(50,50,56) to rgba(36,30,26) with a subtle top border accent
• Shadow fix: removed wide-spread glow layers (60-80px) that were being clipped by the native window transparent padding

Test Plan

• 472 frontend tests pass (bun run test)
• Full validate-build passes with zero warnings/errors
• Visual: compact ask-bar mode shows warm surface + glow at top
• Visual: expanded chat mode maintains same treatment, smooth morph
• Visual: no shadow clipping at window edges

🤖 Generated with Claude Code

[quiet-node]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.

🤖 Generated with Claude Code

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