Refine FinSight research workspace

[juanjuandog]

What changed

• Rebuilt the frontend around five focused research workspaces: company research, AI analysis, evidence, events, and watchlist.
• Added the white-gold FinSight shell, responsive navigation, focused chart and collection/workspace styles.
• Added global evidence search while preserving company-scoped retrieval.
• Removed legacy compatibility UI, obsolete preview code, redundant requests, and the unused PNG brand asset.
• Added a reusable FinSight product design system for future UI work.

Why

The previous console mixed engineering diagnostics, user workflows, evidence, events, and watchlists on one dense page. The new structure keeps the main company view focused and moves supporting workflows into dedicated workspaces.

Impact

Users get a calmer, clearer research flow without changing the underlying research-task, retrieval, market-data, event, or watchlist APIs. The cleanup also reduces unnecessary frontend requests and removes dead code.

Validation

• node --check backend/src/main/resources/static/app.js
• DOM reference audit: all 41 referenced IDs exist
• mvn clean test: 12 tests, 0 failures, 3 Docker-dependent tests skipped because Docker was not running
• Read-only frontend main-flow audit passed for workspace switching, event bindings, mobile navigation, and deleted-resource references