fix: serialize advertising spend cap checks

[lalalune]

Fixes #11800

Summary

• serialize account spend-cap allocation checks with per-account transaction advisory locks for campaign create, budget increases, and cap updates
• lock the ad account row during serve debits so concurrent campaigns cannot write-skew the account cap
• add service coverage for a provider-accepted budget increase that loses the serialized cap race and verifies refund + provider revert

Evidence

• .github/issue-evidence/11800-ad-spend-cap/README.md

Verification

• bun install - pass after rebase; artifact sync side effects removed from branch
• bun test packages/cloud/shared/src/lib/services/__tests__/ad-campaign-credit-reconciliation.test.ts - pass, 14 tests
• bun test packages/cloud/shared/src/lib/services/__tests__/ad-account-approval.test.ts - pass, 20 tests
• bun test packages/cloud/shared/src/lib/services/__tests__/ad-inventory.test.ts - pass
• bun run --cwd packages/cloud/shared lint - pass
• bun run --cwd packages/cloud/shared typecheck - pass
• git diff --check - pass
• bun run verify - fails before workspace lint/typecheck on existing audit:type-safety-ratchet: ?? "" is 616 / 615

Evidence N/A

• Frontend screenshots/video: N/A - backend concurrency fix
• Real LLM trajectories: N/A - no agent, prompt, model, or provider behavior changed

[greptile-apps]

Your trial has ended. Reactivate Greptile to resume code reviews.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on this repository. Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: ceceae06-0cd5-426c-8ceb-eeabbe72345a

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/11800-ad-spend-cap

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[greptile-apps]

Your trial has ended. Reactivate Greptile to resume code reviews.

[lalalune]

Rebased #11824 onto current origin/develop after #11822 and revalidated on 5c6f1288e2.

Validation:

• bun test packages/cloud/shared/src/lib/services/__tests__/ad-campaign-credit-reconciliation.test.ts -> 14 pass
• bun test packages/cloud/shared/src/lib/services/__tests__/ad-account-approval.test.ts -> 20 pass
• bun test packages/cloud/shared/src/lib/services/__tests__/ad-inventory.test.ts -> 17 pass
• bun run --cwd packages/cloud/shared typecheck -> pass
• bunx biome check on touched repository/service/test files -> pass
• git diff --check origin/develop...HEAD -> pass

Reviewed the money-path behavior: allocation/cap updates now serialize per account, serve debits lock the account row before the aggregate cap check, and provider-accepted budget/create operations refund and revert/delete the provider object if the final serialized local cap check loses a race.

[lalalune]

Local validation after rebase onto current develop:

• bun run install:light
• bun run --cwd packages/core build
• bun run --cwd packages/shared build
• bun test packages/cloud/shared/src/lib/services/__tests__/ad-campaign-credit-reconciliation.test.ts — pass, 14 tests
• bun test packages/cloud/shared/src/lib/services/__tests__/ad-account-approval.test.ts — pass, 20 tests
• bun test packages/cloud/shared/src/lib/services/__tests__/ad-inventory.test.ts — pass
• bun run --cwd packages/cloud/shared lint — pass
• bun run --cwd packages/cloud/shared typecheck — pass
• git diff --check HEAD — pass

[claude]

Claude encountered an error —— View job

---

I'll analyze this and get back to you.