fix: settings Modified filter now correctly detects nested setting changes (fixes PlatformNetwork/bounty-challenge#21918)

[echobt]

Fix for PlatformNetwork/bounty-challenge#21918: Modified filter counts wrong (shallow comparison)

Changes

• Added countDeepDifferences() function that recursively compares nested settings objects
• The Modified filter badge now shows the correct count for settings with nested sub-objects (e.g., editor.inlayHints, editor.semanticHighlighting)
• Previously, a shallow comparison would count an entire nested object as 1 difference even if multiple sub-settings were changed

Files Modified

• src/components/SettingsDialog.tsx
• src/context/SettingsContext.tsx

[echobt]

Closing: this fix has already been applied directly to the main branch. The branch is based on an older commit and merging it would regress other fixes. The referenced issue is resolved on main.