Add member history tracking and enhance process detail view

[Danil-Didkovskiy]

Previously, the process detail view showed a single CPU/Memory usage value for the current moment. This PR replaces it with a graph that tracks changes:

This makes the view more useful and easier to understand. When reviewing child processes, users can now see how much each process consumed at a specific tick.

The current implementation reuses existing graph components and data aggregation logic.

P.S. This is the final polish step before the 1.0.0 release.

[Copilot]

Pull request overview

This PR upgrades the process detail view from a single “current value” readout to a time-series experience by retaining per-process history (CPU/memory totals) and per-tick member breakdowns, enabling accurate inspection of grouped processes at any historical tick.

Changes:

• Added “picked” (click) vs “scrubbed” (hover) index behavior so clicking off-data can resume live, while hover continues to clamp.
• Introduced selective sampling and storage of metric histories and per-tick group member breakdowns, with buffering while inspecting a pinned tick.
• Updated process grouping behavior to list system daemons as normal singleton rows (no synthetic “System” bucket), and refreshed UI/graphs to support pinned tick inspection.

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/unit/sample-history.test.ts	Adds unit coverage for click-pick vs hover-scrub index mapping.
tests/unit/process-list.test.ts	Updates expectations for daemon grouping and adds tests for selective sampling + member breakdown sampling.
tests/unit/process-detail.test.ts	Adds tests for ranking/rendering stored historical member breakdowns.
src/renderer/index.css	Adds panel pin-in/out animations with reduced-motion support.
src/renderer/domain/sample-history.ts	Adds pickedIndexAtFraction to distinguish click picking from hover scrubbing.
src/renderer/domain/process-list.ts	Removes synthetic System bucket, adds member breakdown sampling and selective sampling APIs.
src/renderer/domain/process-detail.ts	Adds rankMemberSamples for historical per-tick member list rendering; removes System-specific flag.
src/renderer/components/processes/use-process-histories.ts	Stores aligned metric + member breakdown trails, buffers ticks while pinned inspection is active.
src/renderer/components/processes/use-process-actions.ts	Simplifies action targeting now that there is no synthetic System group.
src/renderer/components/processes/process-row.tsx	Removes System-icon special casing in row rendering/equality.
src/renderer/components/processes/process-icon.tsx	Removes gear glyph path; uses the neutral fallback glyph consistently.
src/renderer/components/processes/process-explorer-view.tsx	Wires inspection state into history freezing; passes member history + icon table to detail view.
src/renderer/components/processes/process-detail.tsx	Implements pinned tick inspection UX and overlay members panel backed by historical member samples.
src/renderer/components/metrics/memory-graph.tsx	Adds optional click-to-pick behavior and pinned-band styling.
src/renderer/components/metrics/cpu-graph.tsx	Adds optional click-to-pick behavior and pinned-band styling.
src/renderer/components/metrics/area-layer.tsx	Extends ScrubBand to visually distinguish pinned vs hover scrubs.

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