fix(dashboard): preserve base price when reselecting paid plan

[charlietlamb]

Summary

• make selecting an already-paid plan a no-op
• preserve the existing paid transition for non-paid plans
• cover the serialized update request so its base price and feature items cannot regress

Verification

• bun test tests/ (328 passed)
• bun run ts
• React Doctor changed-files scan (100/100)

---

Summary by cubic

Fixes a bug where reselecting the Paid plan in the plan editor could wipe the base price or feature items. Selecting Paid on an already-paid plan is now a no-op; switching from a non-paid plan to Paid still applies the expected defaults.

• Bug Fixes
  • Preserve existing base price and feature items when Paid is reselected.
  • Keep non-paid → Paid transition behavior; added a unit test to ensure the serialized update request remains intact.

^{Written for commit 747eafd. Summary will update on new commits.}

Greptile Summary

This PR preserves paid-plan pricing when the paid option is selected again. The main changes are:

• Bug fixes: Treat an already-paid plan selection as a no-op.
• Improvements: Move paid-plan selection logic into a typed utility.
• Improvements: Add a test covering preserved price and feature items in the update request.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.

Important Files Changed

Filename	Overview
vite/src/views/products/plan/components/edit-plan-details/PlanTypeSection.tsx	Uses the new helper when the paid plan option is selected.
vite/src/views/products/plan/utils/selectPaidPlanType.ts	Preserves an existing paid product and retains the previous free-to-paid transition.
vite/tests/views/products/plan/plan-type-section.test.ts	Tests that paid-plan price and feature items survive update-request serialization.

_{Reviews (1): Last reviewed commit: "fix(dashboard): 🐛 preserve base price w..." | Re-trigger Greptile}

Context used:

• Context used - When generating the key changes section of the sum... (source)

[capy-ai]

Capy auto-review is paused for this organization because the usage-cycle auto-review limit has been reached. Increase the limit or turn it off in billing settings to resume automatic reviews.

[cubic-dev-ai]

No issues found across 3 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

_{Re-trigger cubic}