ref(snapshots): Add shared context for snapshots react code

[NicoHinderling]

Refactors the snapshot viewer React code to reduce prop drilling via a shared context, and improves several UX patterns:

Shared context (SnapshotViewerContext)

• Extracts viewer state (view mode, diff mode, overlay color, selection, navigation, etc.) into a React context, replacing 20+ props threaded through SnapshotMainContent → child components. Sidebar and main content now consume state via useSnapshotViewer().

URL-driven state

• Moves viewMode, sortBy, and filter state from localStorage/component state to URL query params with history: 'push', so browser back/forward navigates between views and selections.

Image buffering for smooth navigation

• Adds useBufferedImageUrl hook that pre-decodes the next image before swapping src, eliminating the white flash when navigating between snapshots in single view.

Sidebar group-based rendering

• Sidebar now renders collapsed groups (by snapshot name) instead of flat items, with aggregated counts per group. Status filter counts are scoped to the active group when one is selected.

Per-image diff threshold (backend)

• ImageMetadata now supports an optional diff_threshold field. The comparison task uses per-image threshold when set, falling back to the global snapshot-level threshold.

Header / card polish

• Compact unified header with project badge and app ID.
• "Go to Base Build" action in overflow menu.
• Double-click card to open in single view; tooltips on icon buttons; hoverable metadata tooltip; dark-mode-aware theme toggle fix.
• Keyboard: Space/Enter both toggle selection; arrow left/right direction corrected for list↔single.

Other

• PR comment links use selectedTypes query param to match the new URL scheme.
• Diff views use display: none toggling instead of conditional rendering to preserve zoom/slider state across mode switches.

[NicoHinderling]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• ref(snapshots): Add shared context for snapshots react code #114390 👈 (View in Graphite)
• ref(snapshots): Add per-image diffThreshold support #114335
• perf(snapshots): Buffer image swap to eliminate flash during single-view navigation #114271
• ref(snapshots): Final UI tweaks #114232
• feat(preprod): Update snapshot header with approval actions #113959
• feat(preprod): Complete the new snapshot viewer toolbar and controls #113994
• feat(preprod): Add view mode toggle between single and list views #113993
• feat(preprod): Add SnapshotListView virtualized list component #113992
• ref(preprod): Replace sidebar disclosure sections with status filter pills #113988
• ref(preprod): Use transparent color sentinel for overlay visibility #113987
• master

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[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[cursor]

Context uses raw API value instead of derived comparisonType

Medium Severity

The context value sets comparisonType: data?.comparison_type (the raw API response), but the old prop-based code passed the locally derived comparisonType variable (line 209), which applies viewOverride logic (viewOverride === 'solo' ? 'solo' : ...) and a 'solo' fallback default. This means the viewOverride URL query parameter is now ignored by all consuming components, and when data?.comparison_type is undefined, the sort dropdown and solo/diff toggle in SnapshotMainContent will behave incorrectly.

Additional Locations (1)

• static/app/views/preprod/snapshots/main/snapshotMainContent.tsx#L106-L108

 

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