Remove AI-generated jargon from comments [No QA]

[marcaaron]

Explanation of Change

Replaces AI-generated jargon in comments and docstrings with plain English throughout source and test files. No logic changes — only comment text and one constant/variable rename.

Changes made:

• fan out → make/send/update (LoadTestState, SearchUpdate, test comments)
• defense in depth → extra guard (crashDiagnostics)
• sentinel (in prose comments) → placeholder/entry/guard entry (navigation, modal history, violations, transactions, etc.)
• UNDEFINED_SENTINEL constant renamed to UNDEFINED_PLACEHOLDER in compoundParamsKey.ts
• Local variable sentinel in useSyncModalWithHistory/index.ts renamed to guardEntry

Function names that use "sentinel" as part of their API (isModalHistorySentinel, getTrailingStringSentinels, stripTrailingModalSentinels) are unchanged to avoid a breaking API rename.

Fixed Issues

$
PROPOSAL:

Tests

1. Run npm run test and verify all unit tests pass (no logic was changed)
2. Verify no TypeScript errors: npm run typecheck-tsgo

• Verify that no errors appear in the JS console

Offline tests

N/A — comment-only changes, no behavior change.

QA Steps

N/A — comment-only changes, no user-visible behavior change.

• Verify that no errors appear in the JS console

PR Author Checklist

• 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

Android: Native

Android: mWeb Chrome

iOS: Native

iOS: mWeb Safari

MacOS: Chrome / Safari

[melvin-bot]

@jasperhuangg Please copy/paste the Reviewer Checklist from here into a new comment on this PR and complete it. If you have the K2 extension, you can simply click: [this button]

[codecov]

Codecov Report

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

Files with missing lines	Coverage Δ
src/components/ConnectToHRFlow/index.ios.tsx	0.00% <ø> (ø)
...s/Modal/useSyncModalWithHistory/modalGuardState.ts	100.00% <ø> (ø)
...onfirmationList/hooks/useConfirmationValidation.ts	89.47% <ø> (ø)
src/components/Popover/index.tsx	0.00% <ø> (ø)
...onents/Search/SearchRouter/SearchRouterContext.tsx	81.81% <ø> (ø)
...ateRootStackNavigator/GetStateForActionHandlers.ts	65.84% <ø> (ø)
.../routerExtensions/addRootHistoryRouterExtension.ts	100.00% <ø> (ø)
...erExtensions/addRootHistoryRouterExtensionUtils.ts	89.47% <ø> (ø)
src/libs/Network/LoadTestState.ts	100.00% <ø> (ø)
src/libs/TransactionUtils/index.ts	90.86% <ø> (ø)
... and 9 more
... and 14 files with indirect coverage changes

[joekaufmanexpensify]

No product review needed

[marcaaron]

Skipping C+ review and checklist because this is mostly a bunch of comment changes.

[github-actions]

🚧 marcaaron has triggered a test Expensify/App build. You can view the workflow run here.

[OSBotify]

✋ This PR was not deployed to staging yet because QA is ongoing. It will be automatically deployed to staging after the next production release.

[github-actions]

🧪🧪 Use the links below to test this adhoc build on Android, iOS, and Web. Happy testing! 🧪🧪
Built from App PR #98062.

Android 🤖	iOS 🍎
https://ad-hoc-expensify-cash.s3.us-east-1.amazonaws.com/rock-artifacts/ad-hoc/rock-android-Adhoc-c867a27cf58-fccb5f6-f0244839388c478e109f320d0149cb1705dacae4/index.html	❌ FAILED ❌
	The QR code can't be generated, because the iOS build failed

Web 🕸️
https://98062.pr-testing.expensify.com

---

👀 View the workflow run that generated this build 👀

[OSBotify]

🚀 Deployed to staging by https://github.com/marcaaron in version: 9.4.53-0 🚀

platform	result
🕸 web 🕸	success ✅
🤖 android 🤖	success ✅
🍎 iOS 🍎	success ✅

[MelvinBot]

🤖 No help site changes required.

I reviewed the changes in this PR against Expensify's help site content under App/docs/articles. This PR only touches internal comments, docstrings, and a couple of code-symbol renames — there is no user-facing behavior, UI, feature, setting, or workflow change to document.

Why no docs update is needed

Every change is internal and non-behavioral:

• Comment/docstring wording swaps (e.g. sentinel → placeholder/guard entry, fan out → send/make, defense in depth → extra guard) across source and test files.
• One constant rename UNDEFINED_SENTINEL → UNDEFINED_PLACEHOLDER in src/libs/compoundParamsKey.ts.
• One local variable rename sentinel → guardEntry in src/components/Modal/useSyncModalWithHistory/index.ts.
• A new coding-standards rule file (.claude/skills/coding-standards/rules/consistency-17-no-ai-jargon.md).

The help site documents customer-facing product behavior, and none of that is affected here. Accordingly, I did not create a draft help site PR.

@marcaaron, please review the linked help site PR and confirm it reflects the current behavior. Then mark the linked help site PR Ready for review.

(Note: no help site PR was created because no docs changes are required — see above.)