Phase 2 of hyperhive#2196. The backend now pre-computes enrichment fields
on every SSE event (stream_enrich.rs); the frontend reads them directly
instead of running its own dispatch logic.
Removed (~330 lines of JS):
- fmtArgsGeneric / TOOL_ICONS / toolIcon / fmtRoom / fmtUser / fmtToolUse
renderStream changes:
- system events: dispatch on v._category (drop/thinking_tok/note/details)
+ v._summary / v._body instead of per-subtype if-chains; status tick
still overrides label client-side when stateName === 'compacting' since
elapsed time is a wall-clock value the backend cannot know at emit time
- tool_use: use c._category === 'rich' for rich-renderer routing,
c._icon / c._summary for flat rows
renderRichToolUse: toolIcon(name) -> c._icon (from backend enrichment)
stream_enrich.rs: also stamp _category: 'drop' on top-level
type=result / type=rate_limit_event so the frontend can use a single
_category check instead of separate type-based early returns
Move per-message rendering logic from frontend JS to backend Rust.
A new stream_enrich::enrich() function stamps display fields onto
LiveEvent::Stream payloads at SSE-emit time (both live tail and history
replay), so the frontend can consume pre-computed fields instead of
re-implementing the dispatch logic in JavaScript.
Phase 1: backend stamps _icon/_summary/_category; client falls back to
its own JS tables when absent. Zero user-visible change.
- system events: _category (drop/thinking_tok/note/details) + _summary
and optional _body (commands_changed expands to a slash-cmd list)
- assistant tool_use entries: _icon + _summary per tool; rich tools
(Write, Edit, send, ask, answer) get _category: 'rich'
- enrichment applied in web_ui/stream.rs at emit time; DB stores raw
events so no migration is needed when enrichment logic changes
- idempotent: existing _-prefixed fields are left unchanged
