refactor(auth): generalize clearLocalStorage with reusable utility

[XyneSpaces]

Type of Change

• Refactoring

Description

Replaced hardcoded clearLocalStorage implementation with a generalized clearLocalStorageExcept utility that accepts getter/setter tuples for keys to preserve.

Changes:

• Added clearLocalStorageExcept() accepting array of (getter, setter) tuples
• Refactored clearLocalStorage() to use new utility
• Maintains backward compatibility — all 6 call sites unchanged
• Preserves: themeId, domain, customTableColumns

Motivation and Context

Closes #2894

The previous implementation hardcoded specific keys (themeId, domain, customTableColumns) making it inflexible. The new utility allows any set of keys to be preserved, improving maintainability.

How did you test it?

• ✅ ReScript build: npm run re:build (2,745 modules compiled successfully)
• ✅ Production build: npm run build (passed with expected size warnings)
• Manual verification: logout flow preserves theme/domain/table preferences

Where to test it?

• INTEG
• SANDBOX
• PROD

Backend Dependency

• No

Feature Flag

• No feature flag changes

Checklist

• I ran npm run re:build
• I ran npm run build
• Code follows existing patterns
• No hardcoded values introduced
• Backward compatible

[semanticdiff-com]

Review changes with  

[XyneSpaces]

Review Summary

Classification: Refactoring — LocalStorage utility generalization
Risk Level: Low
Files Changed: 1 file (CommonAuthUtils.res)

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Verification Against Control Center Checklist

Tier 1 — Naming Consistency:
✅ Function name clearLocalStorageExcept clearly indicates purpose (clear except specified keys)
✅ Parameter name keysToPreserve accurately describes the array of getter/setter tuples
✅ Follows existing camelCase convention for utility functions

Tier 2 — Reuse & Hygiene:
✅ Uses existing LocalStorage.clear() API correctly
✅ Leverages existing Array.map, Array.forEachWithIndex patterns
✅ Proper Option handling with Some(Some(value)) pattern

Tier 3 — Backward Compatibility:
✅ Original clearLocalStorage() function signature unchanged
✅ All 6 existing call sites remain functional
✅ Same keys preserved (themeId, domain, customTableColumns)

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Findings

None. Clean refactoring that improves maintainability while preserving existing behavior.

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Verdict: ✅ Approve — Well-structured utility extraction with no breaking changes.