[Feat] timeline zoom & precision controls in enlarged time filter

[jmalmo]

Summary

This PR adds cursor-centric zoom and precise navigation to the enlarged time filter (bottom timeline):

• Wheel → zoom active window around cursor.
• Pinch / hold Ctrl (⌘ on Mac) + wheel → zoom entire timeline domain (shows a “Showing … Reset” banner with one-click reset).
• Keyboard pan → Ctrl/⌘ + ←/→ (hold Shift for larger steps).
• Window and animation stay clamped to the full data domain; updates are throttled to minimize Redux churn.

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Related issues

Addresses timeline precision and usability gaps reported in
#743, #788, #1101, #2541, and #2991.
Closes #743, #788, #3231 .

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Why

Selecting narrow time intervals in the timeline has been difficult with only range handles.
This feature improves precision and usability when exploring datasets with second-level or sub-minute events.

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User-facing changes

• New zoom/pan interactions in the enlarged time filter only (no change to the compact side-panel slider).
• A small “Showing … Reset” banner appears whenever the visible domain is narrowed.

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Implementation notes

• time-widget.tsx
  • Centralizes cursor-driven interactions.
  • Adds local timelineDomain state separate from the main filter range.
  • Implements wheel & pinch zoom, keyboard panning, domain/window clamping, and throttled updates (40 ms).
  • Adds “Showing … Reset” status bar with reset button.
• time-range-slider.tsx
  • Cancels throttled onChange on unmount to prevent lingering timers.
• histogram-plot.tsx
  • Simplifies isBarInRange: bar is in range if it overlaps the active window (bar.x1 > start && bar.x0 < end), ensuring consistent highlights for zoomed domains.
• Docs (docs/user-guides/h-playback.md)
  • Adds a new “Zoom & precision controls” section describing wheel/pinch zoom, reset banner, and keyboard panning.

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Performance & accessibility

• Wheel/pinch events are throttled and use passive: false only where necessary to prevent browser zoom.
• Keyboard navigation (Ctrl/⌘ + arrow keys, Shift for larger steps) improves accessibility.
• All logic is isolated to the enlarged widget; no impact on saved configs or GPU filtering.

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Backwards compatibility

• No schema or API changes.
• timelineDomain is purely UI state.
• Saved maps load without modification.

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How to test

1. yarn install && yarn bootstrap (root), then yarn start or yarn start:local in examples/demo-app.
2. Load a dataset with a timestamp column (e.g., second-level events).
3. Add a Time filter, click Enlarge (bottom timeline).
4. Try:
   • 🖱️ Wheel to zoom the window.
   • 🤏 Pinch or hold Ctrl/⌘ + wheel to zoom the timeline domain.
   • ⌨️ Ctrl/⌘ + ←/→ to pan (hold Shift for larger steps).
   • Click Reset to restore the full domain.
5. Verify histogram highlights and playback behavior remain consistent.

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Checklist

• DCO sign-off on all commits (git commit -s …)
• Lint & tests pass (yarn lint && yarn test)
• Docs updated (docs/user-guides/h-playback.md)
• Manual QA with dense, second-level datasets
• No breaking changes

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Screenshots / GIFs

1️⃣ Wheel zoom on active window

Show how scrolling directly over the timeline zooms in/out on the visible playback window around the cursor position.

2️⃣ Pinch or Ctrl(⌘)+wheel zoom of full timeline + Reset banner

Demonstrate pinch zoom or Ctrl(⌘)+scroll zooming the entire domain, and how the “Showing … Reset” banner appears.
Show the banner’s visibility state and how clicking Reset restores the full timeline domain.

3️⃣ Keyboard panning

Demonstrate holding Ctrl(⌘) and pressing ← / → to pan, and adding Shift for larger steps.

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Notes for reviewers

All changes are isolated to UI components and documentation.
No schema or public API modifications.
Focus review on timeline interaction behavior, clamping logic, and throttling performance.