Tracing Tables

Per-mount local state for the tracing table surfaces (observations, later traces), following the local-store pattern from .agents/skills/frontend-large-feature-architecture.

Owner Map

• observations/observationsTableStore.ts — vanilla zustand store owning row selection, select-all, selected-page-row derivation, and the add-to-dataset dialog flag. Pure logic, covered by observationsTableStore.clienttest.ts.
• observations/useObservationsTableView.ts — creates the store per mount (lazy useState) and bridges the URL/session-storage useSelectAll state into it.
• observations/ObservationsTableStoreProvider.tsx — feature-scoped context for feature components (toolbar, dialogs). Shared components never consume this context: DataTable and TableSelectionManager receive the store explicitly via the selectionStore prop (web/src/components/table/table-selection-store.ts), so nested tables (e.g. ScoresTable inside the observation peek) are unaffected.

State Boundaries

• Selection state: this store.
• Server/query state: tRPC in the table use-case component.
• Route/filter state: URL hooks in the table use-case component (frozen — see below).

Status / Remaining Spread

ObservationsTable (web/src/components/table/use-cases/observations.tsx) is still a controller component: inline column building, query-state assembly from multiple hooks, and data preparation in render. Per the 2026-06 decision, the legacy observations page is frozen (bugfix-only); the filtering/search vertical is being rebuilt behind a flag rather than migrated further. The selection store and the context-free DataTable selection API from this folder are reused by the rebuilt surface.