[PHOTO-014] Timeline, map, folders, favorites, and on-this-day

[veryCrunchy]

Parent epic: #14

Roadmap

• Task ID: PHOTO-014
• Priority: P1
• Status: in progress

Goal

Provide complete, native Photos and Memories navigation for large libraries without requiring the user to load the entire collection first.

Progress

• Incrementally page the complete Memories timeline.
• Group media chronologically and retain stable state across refreshes.
• Navigate distant months and years with an edge scrubber backed by the complete day index.
• Browse server folders with direct and recursive scopes, search, list/grid controls, and representative photo mosaics.
• Keep RAW/TIFF and stacked media available in the timeline and folder views.
• Add the native map experience.
• Add favorites as a first-class destination.
• Add on-this-day memories and their empty/loading/error states.

Acceptance criteria

• Each mode has native navigation, paging, filters, and stable state.
• Large libraries remain bounded and responsive on Android and desktop.
• Back navigation, keyboard, pointer, touch, and accessibility semantics are deterministic.
• Synthetic visual QA covers the important compact, expanded, loading, empty, and recoverable error states.