fix(photo-addon): improve calendar navigation and zoom controls

[paul43210]

Summary

• Fix year/month dropdown selectors not triggering navigation
• Show "No photos found for [Month Year]" with "Jump to nearest photos" button instead of silently falling back
• Bidirectional scroll loading: older photos on scroll down, newer on scroll up (with scroll position preservation)
• Sync dropdowns to currently visible date group while scrolling
• Add +/- zoom buttons (Day ↔ Week ↔ Month ↔ Year) matching pinch-to-zoom behavior
• Fix premature loading stop when scrolling back (broken empty batch detection)
• Clarify EXIF only toggle tooltip (Photo app: identification if exif or not #357)

Test plan

• Select a year/month with photos — verify they load and display
• Select a year/month with no photos — verify empty state message appears
• Click "Jump to nearest photos" — verify it finds and displays nearest month
• Scroll down to load older photos, scroll up to load newer photos
• Verify dropdowns update as you scroll through different months
• Test +/- zoom buttons cycle through Day → Week → Month → Year
• Verify EXIF only toggle tooltip text is accurate

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