MPDX-9617 Fix Credit Card Fees formula percent precision in PDS Goal Calculator

[wjames111]

Description

• Fixes the Credit Card Fees formula label on the Support Item step of the PDS Goal Calculator
• The label rounded the configured CREDIT_CARD_FEE_RATE.fee (0.006 / 0.6%) to "1%" because percentageFormat defaulted to 0 fraction digits, while the underlying calculation correctly used 0.6%
• Pass fractionDigits: 2 to percentageFormat at the credit-card-fees call site so the formula renders "0.60%" and matches the math
• Adds a regression test pinning the formula text for a fractional fee rate
• Jira: MPDX-9617

Testing

• Go to /accountLists/<id>/hrTools/pdsGoalCalculator/<goalId> on staging (impersonate sarah_1.single_staff_applicant@cru.org, designation 1334191) or create a default-type PDS goal
• Complete the Setup step with any valid pay/hours/benefits
• Open the Support Item step
• Check that the Credit Card Fees row formula reads (Subtotal + Attrition) ÷ (1 - 0.60%) - (Subtotal + Attrition) (no more "1%")
• Confirm the dollar amount is unchanged (the calculation was always correct — only the label was wrong)
• Run yarn jest src/components/HrTools/PdsGoalCalculator/SupportItem/otherBreakdown.test.tsx and confirm all tests pass

Checklist:

• I have given my PR a title with the format "MPDX-(JIRA#) (summary sentence max 80 chars)"
• I have applied the appropriate labels (Add the label "Preview" to automatically create a preview environment)
• I have run the Claude Code /pr-review command locally and fixed any relevant suggestions
• I have requested a review from another person on the project
• I have tested my changes in preview or in staging
• I have cleaned up my commit history

🤖 Generated with Claude Code

[github-actions]

Bundle sizes [mpdx-react]

Compared against 4a5f134

No significant changes found

[wjames111]

Multi-Agent Review Summary — PR #1796

Verdict: APPROVED WITH SUGGESTIONS

Risk: LOW (1/10) — Single display-precision fix in a goal-calculator component, well-scoped and covered by a new unit test. The change correctly keeps rounding at the display boundary via Intl.NumberFormat (per the project's Financial Reporting rule). No calculation logic touched; totals.creditCardFees still uses the raw creditCardFeeRate with full precision.

Agents: Architecture, Testing, Standards, UX, Financial Reporting (5 agents, parallel)

Findings at a glance

Severity	Count	Summary
Critical (9-10)	0	—
High (8-8.9)	0	—
Important (7-7.9)	0	—
Medium (5-6.9)	1	Cross-rate consistency (3 agents)
Suggestion (<5)	5	Edge-case tests, FYIs

Highlights

• 3-agent consensus (Architecture + UX + Financial Reporting): Consider extending { fractionDigits: 2 } to the sibling attritionRate (line 110) and adminRate (line 137) calls in the same file. They flow from the same upstream shape (fee: Float!) and the same pdsGoalConstants.ts source — the same misrepresentation bug class can recur there. Out of scope for the MPDX-9617 ticket but worth a follow-up.
• Testing: New assertion is correct and matches the project's i18next test convention (precedent: same file line ~220 asserts a resolved string for the attrition row). Edge-case coverage could be expanded (0, 0.0001, 0.03).
• Standards: Clean across every applicable checklist item — named exports, i18n preserved, no any, no debug output, no new Date(), colocated test.
• Financial Reporting: Fix exemplifies the "round at the display boundary" rule. Calculation path verified untouched.

Notes (informational, not actionable in this PR)

• .CLAUDE/rules/code-review.md references src/components/Reports/PdsGoalCalculator/** for the Financial Reporting agent trigger, but the actual location is src/components/HrTools/PdsGoalCalculator/**. Worth a separate rules-file update so future automated review fires the right domain agent.

[wjames111]

[Medium] **Cross-rate consistency** — 3 agents (Architecture, UX, Financial Reporting) all flag the same point: the sibling `attritionRate` (line 110) and `adminRate` (line 137) still call `percentageFormat` without `{ fractionDigits: 2 }`. They share the same upstream shape (`fee: Float!` in `schema.graphql`) and the same source in `pdsGoalConstants.ts`, so the same misrepresentation bug class can recur there (e.g., a 6.5% attrition rate would render as `7%`). The sibling `PdsSummaryTable.tsx:69` already standardizes on 2-decimal precision for PDS rates.

Out of scope for MPDX-9617 (the ticket is scoped to Credit Card Fees), but recommended as a small follow-up to close the bug class. If you keep the scope tight, a tiny helper at the top of the file would prevent option-object duplication when you do extend it:

const formatRate = (value: number, locale: string) =>
  percentageFormat(value, locale, { fractionDigits: 2 });

[wjames111]

[Suggestion] **Sub-basis-point precision is truncated (FYI)** — `fractionDigits: 2` will round anything below 0.005% to `"0.00%"`. For typical credit-card fee rates this is the right trade-off (and is exactly the project's "round at the display boundary" rule), but worth noting that if PDS ever configures rates with more than basis-point precision, the displayed rate won't exactly match the un-rounded value used in the `amount` calculation. No action needed.

[github-actions]

AI Review Auto-Approval

Risk Level: LOW (1/10)
Verdict: APPROVED_WITH_SUGGESTIONS (suggestions posted, no blockers)

This PR was auto-approved because:

• The multi-agent AI review determined it is low risk
• No blocking issues were found
• All suggestions have been posted as review comments for the developer to consider

If you believe this PR needs human review, dismiss this approval and request a review manually.

[zweatshirt]

Sorry this test failure (chunk 2) has been driving me crazy. It's a timeout. I'll fix that, hopefully will be sorted out soon.
00d38f7