Revert source-map disable from #50579 (re-enable Sentry source maps for studio) (#50581)

<!-- ccr-slack-attribution -->
_Requested by **Ali Waseem** · [Slack
thread](https://supabase.slack.com/archives/C0161K73J1J/p1789738618897549?thread_ts=1789738618.897549&cid=C0161K73J1J)_

**Before:** #50579 disabled Sentry source-map generation and upload for
`apps/studio` (`sourcemaps: { disable: true }` in
`apps/studio/next.config.ts`), as a same-day attempt to fix Vercel
Preview builds OOMing during compilation.

**After:** Sentry source maps are re-enabled for `apps/studio` by
removing that option, restoring the file to its exact pre-#50579 state
for this line.

Disabling source maps turned out not to fix the OOM issue after all —
builds still hung. The actual fix was switching Vercel to Elastic Build
Machines (an infrastructure setting, not a code change), which brought
build times down to ~4 minutes. Since source maps are valuable for
Sentry crash visibility and are no longer needed to work around the OOM,
this PR re-enables them.

Note on scope: `output: 'standalone'` in `apps/studio/next.config.ts` is
left untouched by this PR. It was removed and then re-added within
#50579 itself (net no change on merge), and it remains present (`output:
'standalone'`) on the current default branch HEAD. Any further
discussion about removing `output: 'standalone'` (raised separately in
the Slack thread) is intentionally out of scope here.

This is a minimal, surgical revert of only the sourcemaps-disable line
from #50579 — it does not touch #50578 (an unrelated Next.js/dependency
version bump) or any other change.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

https://claude.ai/code/session_01UqvBiopu7KUqAkQNvEnkoJ


---
_Generated by [Claude
Code](https://claude.ai/code/session_01UqvBiopu7KUqAkQNvEnkoJ)_

Co-authored-by: Claude <noreply@anthropic.com>

apps/studio/next.config.ts

@@ -221,7 +221,6 @@ export default process.env.NEXT_PUBLIC_IS_PLATFORM === 'true' && process.env.VER
   ? withSentryConfig(platformConfig, {
       silent: false,
       debug: true,
-      sourcemaps: { disable: true },
 
       // For all available options, see:
       // https://docs.sentry.io/platforms/javascript/guides/nextjs/manual-setup/