phsl / new-api

feat(api):
• Add optional `type` query param to `/api/channel` endpoint for type-specific pagination
• Return `type_counts` map with counts for each channel type
• Implement `GetChannelsByType`, `CountChannelsByType`, `CountChannelsGroupByType` in `model/channel.go`

feat(frontend):
• Introduce type Tabs in `ChannelsTable` to switch between channel types
• Tabs show dynamic counts using backend `type_counts`; “All” is computed from sum
• Persist active type, reload data on tab change (with proper query params)

perf(frontend):
• Use a request counter (`useRef`) to discard stale responses when tabs switch quickly
• Move all `useMemo` hooks to top level to satisfy React Hook rules
• Remove redundant local type counting fallback when backend data present

ui:
• Remove icons from response-time tags for cleaner look
• Use Semi-UI native arrow controls for Tabs; custom arrow code deleted

chore:
• Minor refactor & comments for clarity
• Ensure ESLint Hook rules pass

Result: Channel list now supports fast, accurate type filtering with correct counts, improved concurrency safety, and cleaner UI.