Fix Seer billing for empty questions

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What changed

• Reject empty/whitespace Ask-the-Seer questions in enforceToolSeerGate before rate-limit and consumeBillingAction, so PAYG credits and free tool-seer instances are not spent on 400s.
• Reject whitespace-only Main Seer message values before debiting main_seer.
• Tests now prove empty/whitespace questions return 400 and never call billing; injection blocks also skip debit.
• Link issue/error report (automated critical-bug investigation).

Why this change is safe

• Root cause identified: the gate skipped empty questions (blockSeerQuestionIfNeeded returns null for "") so the route could return 400, but billing was later added inside the gate before that 400.
• Scope is focused (gate + main Seer chat + unit tests). No refund helper, no billing-order refactor for LLM failures.
• Risk areas reviewed: auth still required; valid questions still bill; injection blocks still run before debit.

Bug and impact

Authenticated PAYG user (or first free tool-seer use) posts {"userId":"<own uid>","question":""} to any /api/ask-*-seer route. The gate billed 1 credit (or burned the free instance), then the route returned 400. Whitespace-only Main Seer messages had the same leak. A client retry loop could drain a credit pack without any LLM call.

Verification

• pnpm exec eslint on touched files (0 errors).
• pnpm test tests/unit/enforceToolSeerGate.test.ts — 6/6 including new empty/whitespace no-bill cases.
• pnpm test — 69 suites / 382 tests passed.
• pnpm run security passed (audit + security lint).
• Playwright smoke (API billing-gate change; no UI routing change).

Regression prevention

• Added tests that fail if empty/whitespace questions reach consumeBillingAction.
• Confirmed a valid question still calls consumeBillingAction after the gate.

Release checklist (solo-friendly)

• CI is green:
  • CI / Lint + Jest
  • CI / Playwright smoke
• Ready to merge to main.
• Post-merge sanity check planned: empty Ask-the-Seer POST returns 400 and credit balance unchanged.

Note

Does not duplicate open #24–#58. Those cover regen lock/hash billing, cache IDORs, and on-demand persist races. LLM-failure refund after a valid question is still unfixed by design.

  

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Project	Deployment	Actions	Updated (UTC)
future-seer	Ready	Preview	Aug 26, 2026 11:15am