[No QA] Add NumberForm root with SymbolInput and TextInput primitives

[jmgraa]

Explanation of Change

This PR introduces the new composable NumberForm foundation and extracts numeric input behavior from the monolithic NumberWithSymbolForm implementation.

NumberForm now provides shared controlled state, external value synchronization, error handling, callbacks, and the imperative ref API through context. It exposes two specialized primitives:

• NumberForm.SymbolInput for inputs using TextInputWithSymbol
• NumberForm.TextInput for standard text inputs

Both primitives use the shared useNumberFormInputLogic hook, which centralizes:

• Locale digit and separator normalization
• Leading-zero handling
• Negative-value handling
• Decimal and maximum-length validation
• Caret and selection updates
• Forward-delete keyboard handling
• External value changes and focus restoration
• Ref forwarding and the clearSelection, updateNumber, and getNumber imperative methods

This differs from NumberWithSymbolForm in that the legacy component combines the form state, numeric input logic, rendering branches, number pad, symbol/currency controls, flip controls, and layout composition in a single component. It also maintains separate setter paths for the symbol input and the standard text-input mode. The new implementation separates the shared numeric behavior from the visual input primitives, allowing future features such as currency buttons and number-pad composition to be added independently.

Normalization is now performed by NumberForm itself. TextInputWithSymbol supports an opt-out flag so that the new component does not normalize the value twice, while the legacy NumberWithSymbolForm behavior remains unchanged.

The new component is introduced as the foundation for subsequent migration work. Dedicated tests cover root state management, both input variants, formatting, validation, ref behavior, external updates, and native selection-event guards.

Fixed Issues

$ #98169
PROPOSAL: #97970

Tests

• Verify that no errors appear in the JS console

Offline tests

N/A

QA Steps

N/A

• 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)
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• 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
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[melvin-bot]

Hey! I see that you made changes to our Form component. Make sure to update the docs in FORMS.md accordingly. Cheers!

[codecov]

Codecov Report

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

Files with missing lines	Coverage Δ
src/components/NumberForm/NumberForm.tsx	100.00% <100.00%> (ø)
...components/NumberForm/context/NumberFormContext.ts	100.00% <100.00%> (ø)
src/components/NumberForm/index.tsx	100.00% <100.00%> (ø)
...ts/NumberForm/primitives/NumberFormSymbolInput.tsx	100.00% <100.00%> (ø)
...ents/NumberForm/primitives/NumberFormTextInput.tsx	100.00% <100.00%> (ø)
...ts/TextInputWithSymbol/BaseTextInputWithSymbol.tsx	100.00% <100.00%> (ø)
...onents/NumberForm/hooks/useNumberFormInputLogic.ts	87.50% <87.50%> (ø)
... and 16 files with indirect coverage changes