feat: render expanded chart at native resolution and add pinch-zoom via MultiGestureCanvas

[abbasifaizan70]

Explanation of Change

Re-renders the expanded chart natively at its target size (via a scaled chart context) instead of raster-upscaling the design-size render, so charts stay sharp on large screens.
Adds pinch/double-tap zoom and pan to the expanded chart using MultiGestureCanvas — the same gestures as the image attachment viewer, as agreed in the follow-up discussion on #95249.
Includes unit tests for the new context-scaling logic.

Fixed Issues

$ #92969
PROPOSAL:#92969 (comment)

Tests

• Verify that no errors appear in the JS console

1. Tap the expand button on the inline chart to open the full-screen modal.
2. Verify the expanded chart is sharp on a large screen (text, axis labels, and lines are crisp, not blurry) and matches the inline chart's layout, only larger.
3. Double-tap (or double-click) the chart and verify it zooms in; double-tap again to zoom back out.
4. Pinch (mobile/trackpad) and verify the chart zooms smoothly within limits.
5. While zoomed in, drag to pan around the chart and verify it stays within bounds.
6. Close the modal and verify the chat is unchanged and no flicker appears.
7. Repeat with a pie chart and verify zoom/pan work and the chart stays clipped/centered like inline.

Offline tests

Same as tests.

QA Steps

• Verify that no errors appear in the JS console

Same as tests.

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)
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• 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
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• 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.
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Screenshots/Videos

Android: Native

Screen_Recording_20260825_014636_New.Expensify.Dev.mp4

Android: mWeb Chrome

Screen_Recording_20260825_015755_Chrome.mp4

iOS: Native

Screen.Recording.2026-08-25.at.12.38.37.AM.mov

iOS: mWeb Safari

Screen.Recording.2026-08-25.at.12.53.26.AM.mov

MacOS: Chrome / Safari

Screen.Recording.2026-08-22.at.5.33.50.AM.mp4

[codecov]

Codecov Report

❌ Looks like you've decreased code coverage for some files. Please write tests to increase, or at least maintain, the existing level of code coverage. See our documentation here for how to interpret this table.

Files with missing lines	Coverage Δ
src/CONST/index.ts	94.85% <ø> (ø)
...ctoryChartRenderer/context/VictoryChartContext.tsx	95.83% <100.00%> (+90.27%)	⬆️
...enderers/VictoryChartRenderer/utils/parseOffset.ts	100.00% <100.00%> (ø)
src/styles/index.ts	63.00% <ø> (ø)
...Renderer/context/VictoryChartRenderArgsContext.tsx	25.00% <50.00%> (ø)
...ChartRenderer/components/VictoryChartCartesian.tsx	0.00% <0.00%> (ø)
...ctoryChartRenderer/components/VictoryChartLine.tsx	9.09% <0.00%> (ø)
...artRenderer/utils/scaleVictoryChartContextValue.ts	96.00% <96.00%> (ø)
...ictoryChartRenderer/components/VictoryChartBar.tsx	8.33% <0.00%> (-0.76%)	⬇️
...artRenderer/components/VictoryChartExpandModal.tsx	2.70% <0.00%> (+0.52%)	⬆️
... and 7 more
... and 36 files with indirect coverage changes

[melvin-bot]

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[situchan]

Reviewer Checklist

• I have verified the author checklist is complete (all boxes are checked off).
• I verified the correct issue is linked in the ### Fixed Issues section above
• I verified testing steps are clear and they cover the changes made in this PR
  • I verified the steps for local testing are in the Tests section
  • I verified the steps for Staging and/or Production testing are in the QA steps section
  • I verified the steps cover any possible 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 checked that screenshots or videos are included for tests on all platforms
• I included screenshots or videos for tests on all platforms
• I verified that the composer does not automatically focus or open the keyboard on mobile unless explicitly intended. This includes checking that returning the app from the background does not unexpectedly open the keyboard.
• I verified tests pass on all platforms & I tested again on:
  • Android: HybridApp
  • Android: mWeb Chrome
  • iOS: HybridApp
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
• If there are any errors in the console that are unrelated to this PR, I either fixed them (preferred) or linked to where I reported them in Slack
• I verified proper code patterns were followed (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 verified that this PR follows the guidelines as stated in the Review Guidelines
• I verified other components that can be impacted by these changes have been tested, and I retested again (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar have been tested & I retested again)
• If a new component is created I verified that:
  • A similar component doesn't exist in the codebase
  • All props are defined accurately
  • The component has a clear name that is non-ambiguous and the purpose of the component can be inferred from the name alone
  • The only data being stored in the state is data necessary for rendering and nothing else
  • The component has the minimum amount of code necessary for its purpose, and it is broken down into smaller components in order to separate concerns and functions
• 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 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.
• For any bug fix or new feature in this PR, I verified that sufficient unit tests are included to prevent regressions in this 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.
• I have checked off every checkbox in the PR reviewer checklist, including those that don't apply to this PR.

Screenshots/Videos

Android: HybridApp

Android: mWeb Chrome

iOS: HybridApp

iOS: mWeb Safari

MacOS: Chrome / Safari

[luacmartins]

@situchan how's review going?

[luacmartins]

@situchan any updates on the review?

[situchan]

Sorry missed this. Will update shortly

[situchan]

@abbasifaizan70 charts not rendering at all

Screen.Recording.2026-08-12.at.4.50.11.PM.mov

production:
(this also has regression. Resize is broken)

Screen.Recording.2026-08-12.at.4.51.14.PM.mov

[abbasifaizan70]

@situchan Looking into these in details.

[abbasifaizan70]

Screen.Recording.2026-08-14.at.2.34.56.AM.mp4

@situchan After the fix demo.

[luacmartins]

@situchan did you get a chance to review the latest commits?

[luacmartins]

@situchan bump

[situchan]

Reviewing shortly

[abbasifaizan70]

Screen.Recording.2026-08-20.at.2.16.15_AM-compressed.mp4

@situchan @luacmartins Test with different types of graphs and aslo did resizing. Can you take a look? Thanks

[situchan]

On desktop web (non-touchable device), I think we should mimic the behavior of normal attachment.
So instead of double click (mobile behavior), use +/- with mouse scroll (not mouse drag)

Curious for @Expensify/design thoughts

Screen.Recording.2026-08-19.at.10.30.20.PM.mov

[shawnborton]

That makes complete sense to me - think of this like viewing any other attachment, so whatever we already do for the various platforms should apply here.

[abbasifaizan70]

@situchan Implemented new Zoom follow and updated videos in the PR description as well.

[luacmartins]

@situchan bump for review