Remove unsafe type assertions from Plaid connection

[KJ21-ENG]

Explanation of Change

Removes six unsafe type assertions from the Plaid company-card connection step. The shared Plaid success metadata union now narrows the web and native institution shapes directly, raw Plaid institution IDs remain strings through the add-card and assign-card data contracts, and an optional company-card domain suffix is removed only when the import request is built. Existing empty-error fallback, missing-institution handling, bank naming, account selection, and import behavior are preserved.

Fixed Issues

$ #94739
PROPOSAL: #94739 (comment)

Count change

Current baseline source:

• config/eslint/eslint.seatbelt.tsv at base e69182c5379d82f41b6c9d6b7c7237d2c1cb0dd1.

Before:

• src/pages/workspace/companyCards/addNew/PlaidConnectionStep.tsx: 6 violations

After:

• src/pages/workspace/companyCards/addNew/PlaidConnectionStep.tsx: 0 violations

Net reduction:

• 6 fewer unsafe type assertion violations.

TSV evidence:

• The verifier restored config/eslint/eslint.seatbelt.tsv byte-for-byte after confirming zero cleanup findings in the target and approved support paths.

Changed files

• src/pages/workspace/companyCards/addNew/PlaidConnectionStep.tsx
• src/libs/actions/Plaid.ts
• src/types/onyx/AssignCard.ts
• src/types/onyx/CardFeeds.ts

Tests

1. Focused formatter and ESLint passed for all four changed files.
2. The verifier-owned focused typecheck produced no authorized-path diagnostic; its only diagnostic was in unrelated src/components/AddressSearch/index.tsx.
3. No changed path is matched by App Jest discovery, so focused Jest was not applicable.
4. git diff --check, exact changed-path proof, and generated-TSV restoration passed.
5. Independent scope, type-safety, and regression reviews were clean on the final diff.
6. Exact-head Fork CI run 32107998656 passed typecheck, lint, format, React Compiler, and Jest at signed commit b16d549be9465de5e1dc0bfaa27e8bef119a5915.

No manual application testing was performed; the evidence above is automated verification and independent review.

Offline tests

N/A: Plaid account linking requires network access, this cleanup does not change networking or offline behavior, and no manual offline testing was performed.

QA Steps

1. As a workspace admin, open Workspace settings > Company cards and start adding cards through Plaid.
2. Complete the Plaid connection on web and verify the selected institution name is shown and its accounts can be imported as before.
3. Repeat the Plaid connection on a native client and verify the institution name and accounts are handled as before.
4. Exit without selecting an institution, and verify the existing flow does not attempt an import or show a new error.

PR Author Checklist

N/A rationale: no intended product behavior, copy, CSS, assets, networking, deeplink, Storybook story, messaging flow, generic component, or new feature/bug flow is introduced. No manual platform, high-traffic-account, offline, console, screenshot/video, staging, or production testing was performed. The web/native metadata shapes and downstream Plaid data contracts were examined during planning and independent review, and exact-head CI covered the full repository checks. Every item below was considered against that scope.

• I linked the correct issue in the ### Fixed Issues section above
• I wrote clear testing steps that cover the changes made in this PR
  • I added steps for local testing in the Tests section
  • I added steps for the expected offline behavior in the Offline steps section
  • I added steps for Staging and/or Production testing in the QA steps section
  • I added steps to cover failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
  • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline)
  • I tested this PR with a High Traffic account against the staging or production API to ensure there are no regressions (e.g. long loading states that impact usability).
• I included screenshots or videos for tests on all platforms
• I ran the tests on all platforms & verified they passed on:
  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I followed proper code patterns (see Reviewing the code)
  • I verified that comments were added to code that is not self explanatory
  • I verified that any new or modified comments were clear, correct English, and explained "why" the code was doing something instead of only explaining "what" the code was doing.
  • I verified any copy / text that was added to the app is grammatically correct in English. It adheres to proper capitalization guidelines (note: only the first word of header/labels should be capitalized), and is either coming verbatim from figma or has been approved by marketing (in order to get marketing approval, ask the Bug Zero team member to add the Waiting for copy label to the issue)
• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I followed the guidelines as stated in the Review Guidelines
• I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
• If a new CSS style is added I verified that:
  • A similar style doesn't already exist
  • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(theme.componentBG))
• If new assets were added or existing ones were modified, I verified that:
  • The assets are optimized and compressed (for SVG files, run npm run compress-svg)
  • The assets load correctly across all supported platforms.
• If the PR modifies code that runs when editing or sending messages, I tested and verified there is no unexpected behavior for all supported markdown - URLs, single line code, code blocks, quotes, headings, bold, strikethrough, and italic.
• If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
• If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
• If the PR modifies a component or page that can be accessed by a direct deeplink, I verified that the code functions as expected when the deeplink is used - from a logged in and logged out account.
• If the PR modifies the UI (e.g. new buttons, new UI components, changing the padding/spacing/sizing, moving components, etc) or modifies the form input styles:
  • I verified that all the inputs inside a form are aligned with each other.
  • I added Design label and/or tagged @Expensify/design so the design team can review the changes.
• I added unit tests for any new feature or bug fix in this PR to help automatically prevent regressions in this user flow.
• If the main branch was merged into this PR after a review, I tested again and verified the outcome was still expected according to the Test steps.

Screenshots/Videos

N/A: no UI or visual behavior changed, and no screenshots or videos were produced.

Changed files (4)

• src/libs/actions/Plaid.ts (reserved support path)
• src/pages/workspace/companyCards/addNew/PlaidConnectionStep.tsx
• src/types/onyx/AssignCard.ts (reserved support path)
• src/types/onyx/CardFeeds.ts (reserved support path)

[codecov]

Codecov Report

✅ Changes either increased or maintained existing code coverage, great job!

Files with missing lines	Coverage Δ
src/libs/actions/Plaid.ts	0.00% <0.00%> (ø)
...kspace/companyCards/addNew/PlaidConnectionStep.tsx	0.00% <0.00%> (ø)
... and 8 files with indirect coverage changes