Restores `hooks/misc/useTrackExperimentExposure.ts`, fixing the
typecheck failure on master that broke the latest Studio production
deploy.
The hook was deleted as dead code in #49719 (it was genuinely unused on
master at the time), but #49534 was in flight and reintroduced a usage
in `plan-presentation.ts`. The two PRs merged cleanly with no textual
conflict, so nothing typechecked the combination until the deploy off
master failed with:
```
plan-presentation.ts(5,44): error TS2307: Cannot find module '@/hooks/misc/useTrackExperimentExposure'
```
**Added:**
- `apps/studio/hooks/misc/useTrackExperimentExposure.ts` — restored
verbatim from before #49719; no longer dead code since
`plan-presentation.ts` imports it
## To test
- `pnpm --filter studio typecheck` passes (verified locally)
- `pnpm knip --workspace apps/studio` no longer flags the hook (verified
locally)
- Studio production deploy succeeds once merged
https://claude.ai/code/session_01XZGr2n1dBzJ7m3DYsGu852
Co-authored-by: Alaister Young <10985857+alaister@users.noreply.github.com>
Removes Studio code that nothing imports, as reported by knip. First PR
in a stack of three: this one is pure deletions, #49720 removes the
unused dependencies, #49721 upgrades knip and adds the CI gate so this
doesn't accumulate again.
Every file was verified with a repo-wide grep for its basename, exported
symbols, and string/dynamic imports before deletion — none are reachable
via `next/dynamic`, a barrel file, or a config.
**Removed:**
-
`Billing/Usage/UsageWarningAlerts/{CPU,RAM,DiskIOBandwidth}Warnings.tsx`
(whole directory)
- `DataWarehouse/FormFooterChangeBadge.tsx` (whole directory)
- `Database/Replication/ReplicationDiagram/EmptyReplicationDiagram.tsx`
- `Integrations/Vercel/OrganizationPicker.tsx`
- `QueryInsights/QueryInsightsTable/QueryInsightsTableRow.tsx`
- `hooks/misc/useTrackExperimentExposure.ts`
- `data/ai/{parse-client-code,sql-policy}-mutation.ts`,
`data/misc/parse-query-mutation.ts`,
`data/database/table-check-rls-mutation.ts`
-
`data/notifications/notifications-v2-{archive-all-mutation,summary-query}.ts`
+ their two now-unused keys in `notifications/keys.ts` (`listV2` kept)
-
`data/platform-apps/platform-app-{update,signing-key-delete}-mutation.ts`
- `DateTimeFormats.DATE_ONLY` and the unused
`Notebooks.{MarkdownCell,LogCell,ChartConfig}` types
**Changed:**
- `ReportPadding` no longer has a duplicate default export; its 9
default importers (observability pages) now use the named export
Not removed: `CONSTRAINT_TYPE`'s unused members mirror the closed set of
`pg_constraint.contype` values, so they're documentation rather than
dead code — suppressed narrowly in #49721's knip config instead.
## To test
- `pnpm --filter studio run typecheck` and `lint:ratchet` pass
- Observability pages (`/project/[ref]/observability/*`) still render
with padding — they're the only code touched, via the `ReportPadding`
import change
- Notifications popover still loads and marks-as-read (the removed keys
weren't used for invalidation)
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **Removed Features**
- Removed CPU, memory, and disk usage warning alerts.
- Removed the Vercel organization picker and empty replication diagram.
- Removed query insights row actions and several SQL assistance tools.
- Removed notification summary and archive-all capabilities.
- Removed platform app update and signing-key deletion actions.
- Removed the form change-count badge and experiment exposure tracking.
- **Refactor**
- Updated observability reports to use the revised report layout export.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Co-authored-by: Alaister Young <10985857+alaister@users.noreply.github.com>
## Summary
Adds session-based deduplication for experiment exposure events.
Previously, exposure events used `useRef` which reset on page refresh,
causing duplicate events. Now events dedupe by PostHog session ID using
`sessionStorage`, firing once per session even across page refreshes.
## Changes
- Add `captureExperimentExposure()` method to `PostHogClient` with
session-based dedupe
- Add `getSessionId()` method to retrieve PostHog session ID
- Create `useTrackExperimentExposure` hook for clean usage
- Migrate existing experiments to new hook:
- RLS option experiment (`/new/[slug]`)
- Realtime button experiment
- Table create generate policies experiment
## How it works
1. Event triggered → if PostHog not ready, queue to `pendingExposures[]`
2. PostHog `loaded` → flush queue through `fireExposureIfNew()`
3. `fireExposureIfNew()` checks
`sessionStorage['ph_exposed:{experimentId}']`
4. If value matches current session ID → skip (already fired)
5. If differs or missing → fire event, store session ID
## Testing
- [x] Tested locally and on preview - verified on project creation page
- [x] PostHog events sent successfully (200 responses)
- [x] Session deduplication working (no duplicate events on page refresh
or org switch)
- [x] Lint passes with 0 errors
**Quick test:**
1. Go to `/new/<org-slug>` project creation page
2. Check `sessionStorage` for `ph_exposed:project_creation_rls_option`
key
3. Refresh page - event should not fire again (same session ID)
## Linear
Resolves GROWTH-608
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* More reliable experiment exposure reporting with session-aware
deduplication, queued delivery, and consent respect to ensure events are
recorded when available.
* **Bug Fixes**
* Prevents duplicate exposure events within a session and avoids firing
exposures without a valid session.
* **Refactor**
* Consolidated disparate exposure-tracking logic into a unified
hook-based approach, simplifying tracking across the app.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
