feat: add maximum tasks in home screen setting

[roomote]

Adds a new UI setting to configure the maximum number of tasks shown in the home screen history preview, since we removed the ability to hide them from the home page, intentionally.

Changes

• Added new "Maximum number of tasks in home screen" setting to UI Settings (0-20, default 4)
• Updated HistoryPreview component to respect the new setting value
• When set to 0, the HistoryPreview component does not render at all
• Added translation keys for the new setting
• Updated all relevant tests to account for the new behavior

Testing

• All existing tests pass
• Added new tests for the setting behavior
• Verified HistoryPreview respects the maxTasksHomeScreen value
• Verified component does not render when value is 0

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Important

Introduces a new UI setting to control the maximum number of tasks displayed on the home screen, affecting the HistoryPreview component and including updates to translations and tests.

• Behavior:
  • Adds "Maximum number of tasks in home screen" setting (0-20, default 4) to UI settings.
  • HistoryPreview component updated to respect new setting; does not render if set to 0.
• Translations:
  • Adds translation keys for new setting in multiple locales.
• Testing:
  • Updates existing tests and adds new tests for setting behavior in maxTasksHomeScreen.test.ts and HistoryPreview.spec.tsx.

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[roomote]

Rooviewer   See task on Roo Cloud

Review completed. All previously flagged issues have been resolved.

• Remove hardcoded maxTasksHomeScreen = 100 override in HistoryPreview.tsx that makes the user setting non-functional

Previous reviews

• 52a57f6: Review #1
• 61a5710: Review #2
• acdf4fe: Review #3
• 47e3b60: Review #4

_{Mention @roomote in a comment to request specific changes to this pull request or fix all unresolved issues.}