fix: remove PgSemaphore to fix the payment deadlock

[ygrishajev]

PgSemaphore is no longer needed in the console API. All operations using it are either logically safe without locking or already idempotent. BatchSigningClientService, the only remaining consumer, is only used for testing or in single instance mode, so a simple in-process Sema(1) is sufficient.

Summary by CodeRabbit

• Refactor
  • Removed distributed PostgreSQL semaphore-based synchronization and replaced with in-process semaphore for relevant billing flows.
  • Simplified concurrency control in payment confirmation, coupon application, and wallet creation flows.
• Tests
  • Removed semaphore-related unit and integration tests and a race-condition test for wallet creation.
• Chores
  • Removed semaphore provider initialization and related integration setup.

[coderabbitai]

📝 Walkthrough

Walkthrough

Removes the distributed PostgreSQL semaphore implementation and decorator usage, deletes related tests and provider initialization, replaces one distributed semaphore with an in-process Sema(1), and removes semaphore-related test setup and a concurrency test.

Changes

Cohort / File(s)	Summary
Core pg-semaphore removal apps/api/src/core/lib/pg-semaphore/pg-semaphore.ts, apps/api/src/core/lib/pg-semaphore/semaphore.decorator.ts, apps/api/src/core/lib/pg-semaphore/pg-semaphore.integration.ts, apps/api/src/core/lib/pg-semaphore/semaphore.decorator.spec.ts	Deleted the pg-semaphore implementation, decorator, integration tests, and unit tests; removed Semaphore types, classes, factory, and decorator logic.
Barrel & provider cleanup apps/api/src/core/lib/pg-semaphore/index.ts, apps/api/src/core/providers/index.ts, apps/api/src/core/providers/pg-semaphore.provider.ts	Removed re-exports and provider initialization (APP_INITIALIZER) for the pg-semaphore provider.
Stripe controller updates apps/api/src/billing/controllers/stripe/stripe.controller.ts	Removed @Semaphore() decorators and Semaphore import from confirmPayment and applyCoupon.
Batch-signing client migration apps/api/src/billing/lib/batch-signing-client/batch-signing-client.service.ts, .../batch-signing-client.service.spec.ts	Replaced distributed semaphore with an in-process Sema(1) (field + acquire/release), updated hasPendingTransactions, and removed SemaphoreFactory usage from tests.
Refill service & tests apps/api/src/billing/services/refill/refill.service.ts, apps/api/src/billing/services/refill/refill.service.spec.ts	Removed @Semaphore() on getOrCreateUserWallet and deleted the concurrency/race-condition test; removed semaphore test setup calls.
Functional tests setup apps/api/test/setup-functional-tests.ts	Removed Postgres/semaphore client initialization and teardown from functional-test setup.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Poem

🐇 I hopped through code where locks once lay,
The pg-guards folded, they hopped away.
One Sema now watches the batch with care,
No cross-node chatter — just quiet air.
A rabbit cheered: simpler, light, and fair.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly and clearly describes the main change: removing PgSemaphore to fix a payment deadlock issue. It accurately summarizes the primary objective of the pull request.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Merge Conflict Detection	✅ Passed	✅ No merge conflicts detected when merging into main

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch feature/sema

---

No actionable comments were generated in the recent review. 🎉

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[ygrishajev]

this is logically redundant. We have it properly implemented on the frontend and if implemented via api - it would not do a double call. in the worst case we could do a refund

[ygrishajev]

apply coupon is already idempotent op in stripe.

[ygrishajev]

user wallet has a unique index on userId so sema is redundant here

[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In
`@apps/api/src/billing/lib/batch-signing-client/batch-signing-client.service.ts`:
- Around line 144-146: hasPendingTransactions currently returns
this.sema.nrWaiting() > 0 which misses in-flight batches; introduce an
activeBatches counter (e.g., this.activeBatches = 0) and update
hasPendingTransactions to check both this.sema.nrWaiting() and
this.activeBatches; increment activeBatches immediately after successfully
acquiring the semaphore in the method that starts a batch (the same place the
tx-signer increments) and decrement it in that method's finally block so
activeBatches accurately reflects in-flight operations and prevents premature
cleanup.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 51.35%. Comparing base (d20789c) to head (448b024).
⚠️ Report is 1 commits behind head on main.

❌ Your project status has failed because the head coverage (75.01%) is below the target coverage (78.00%). You can increase the head coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2720      +/-   ##
==========================================
- Coverage   52.24%   51.35%   -0.89%     
==========================================
  Files        1057     1019      -38     
  Lines       28032    27136     -896     
  Branches     6357     6255     -102     
==========================================
- Hits        14644    13937     -707     
+ Misses      12953    12774     -179     
+ Partials      435      425      -10     

Flag	Coverage Δ		*Carryforward flag
api	75.01% <100.00%> (-0.19%)	⬇️
deploy-web	37.19% <ø> (ø)		Carriedforward from d20789c
log-collector	?
notifications	87.94% <ø> (ø)		Carriedforward from d20789c
provider-console	81.48% <ø> (ø)		Carriedforward from d20789c
provider-proxy	84.35% <ø> (ø)		Carriedforward from d20789c
tx-signer	?

*This pull request uses carry forward flags. Click here to find out more.

Files with missing lines	Coverage Δ
...rc/billing/controllers/stripe/stripe.controller.ts	0.00% <ø> (ø)
...tch-signing-client/batch-signing-client.service.ts	87.96% <100.00%> (-0.22%)	⬇️
.../api/src/billing/services/refill/refill.service.ts	97.95% <ø> (ø)

... and 35 files with indirect coverage changes

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