feat(billing): expose netRemainingRaw in useMeter — show negative quota for in-flight jobs #4060

Audit finding (LOW — post-launch)

src/modules/billing/composables/billing.useMeter.js:100:

const totalRemaining = computed(() => Math.max(0, quota.value - used.value) + extras.value);

The Math.max(0, ...) clamp prevents the UI from displaying a negative quota. Memo edge case 1: "Quota négatif autorisé pour jobs en cours, bloque nouveaux. Affichage du négatif en UI".

Currently a user whose attribution has pushed meterUsed > meterQuota (long-running scrap finishing past quota) sees totalRemaining = 0 + extras instead of e.g. -150 + 5000 = 4850 with the negative debt visible.

Proposed fix

Expose both:

const totalRemaining = computed(() => Math.max(0, quota.value - used.value) + extras.value);
const netRemainingRaw = computed(() => quota.value - used.value + extras.value);
const overage = computed(() => Math.max(0, used.value - quota.value));

return {
  // ...existing
  totalRemaining,
  netRemainingRaw,
  overage,
};

UI components decide which to display:

• MeterProgress: keep clamped (visual progress bar, 0-100%)
• Drawer / detail views: show overage chip when overage > 0
• ExtrasLedger: show netRemainingRaw when displaying the bottom-line balance (can be negative when in-flight job runs past quota)

Tests required

• totalRemaining >= 0 always (regression)
• netRemainingRaw can be negative when used > quota and extras=0
• overage is 0 when used <= quota, positive otherwise

Files

• src/modules/billing/composables/billing.useMeter.js
• Components consuming totalRemaining — review and decide which need raw vs clamped
• tests/billing.useMeter.unit.tests.js (add scenarios)

Audit context

Source: codex billing audit. POST-LAUNCH — visual issue, not a billing correctness issue.