[TheGreatAxios]

Summary

Owner ruling: the hub mounts nothing Workbench-specific. packages/insights (usage, activity, tool-call, turn-latency, run-trace, and cross-workbench-scope routes plus their Postgres writers) is deleted along with its ${TENANT_PREFIX}/insights mount in apps/hub/src/index.ts. The stock observability routes it could have read instead (vendor/intx/hub-api/src/routes/observability.ts's four GET routes: agent logs, agent metrics, list traces, get trace) are unimplemented — each returns { error: "not_implemented" }, 501. With no data source left, usage/cost, activity, tool-call, latency, run-trace, and cross-workbench scope switching are dropped rather than faked.

Insights now reads only the native tenant-scoped GET /workflows/runs listing (already used since CL-8087) for its KPI row, "running now" strip, recent runs, and run history grouped by definition.

packages/insights's turn-text-snapshot reader (chat message-edit replay) has no dependency on the deleted usage/latency tables — it reads only native inference_turn/turn_part rows — so it moves to apps/hub/src/turn-text-snapshot.ts instead of disappearing with the rest of the package.

scripts/db-setup.ts forward-drops the insights Postgres schema for existing databases, per docs/package-migrations.md's convention (same pattern as the existing run_key_history/preferences drops).

UI dropped (no stock source)

• Cost/token KPIs (Cost, Tokens in/out, cache-hit rate, token mosaic) — read packages/insights' usage store; no replacement writer exists.
• Activity chart (turns/tokens per day) — same usage-store dependency.
• Cost by model / calls by tool tables — same.
• Turn latency tiles (p50/p95 stage timings, CL-6257) — read the deleted turn_latency table; the vendored event collector never persisted the raw events another reader could recompute from.
• Cross-workbench "activity by workbench" chart and the landing scope switcher ("All workbenches" vs. sibling workbenches) — both read /scope and /workbenches, rolled up from the deleted usage store.
• Run-detail trace waterfall (steps/completed/failed/duration, timeline) — derived from /runs/:runId/trace, which read the deleted trace-reader.ts.
• Sidebar's "Weekly usage" account-menu line — read the deleted /usage route; the sidebar's Insights-nav-row gating now checks for any top-level run instead of usage turns.
• Mission Control's "Runs today" / "Spend today" KPI tiles and "This week" panel — same usage-store dependency.

What's kept: the Insights landing's Runs/Errored/Deployed/Running-now KPIs, the "running now" strip, recent runs, and runs history grouped by definition — all backed by the native GET /workflows/runs feed already used since CL-8087. The per-workbench Insights route (/insights/workbench/:workbenchId) is untouched — it renders WorkbenchTimelineRoute, a chat/run timeline with no dependency on packages/insights.

Deleted tests

Per the hard-cutover ruling, tests encoding the deleted behavior were deleted rather than adapted:

• apps/web/test/insights-page.test.tsx — the full usage/activity/scope-switcher/trace-timeline/workbench-activity/latency-tile render suite (878 lines), superseded by the trimmed suites in apps/web/src/pages/insights-page.test.ts and insights-page-render.test.tsx for the surviving run-list behavior.
• packages/insights/** tests (all of them, with the package).
• insights-stats.test.ts's computeTraceStats and filterRunsByCreatedAt describe blocks (both functions deleted — no trace/range data left to test).
• mission-control-page.test.tsx's three "Runs today"/"Spend today"/"This week" tests.
• sidebar.test.tsx's "Weekly usage" zero-spend test.

Test plan

• bun run typecheck
• bun run lint
• bun run check:structural
• bun --cwd apps/web test (814 pass)

[linear-code]

CL-8160