The single-clip razor path guards splits with isSplitTimeWithinBounds,
which keeps a SPLIT_BOUNDARY_EPSILON_S margin from each clip edge so a
cut never produces a degenerate near-zero slice. The split-all path
filtered with raw `splitTime > start && splitTime < end` instead, so it
accepted cuts inside that margin (and on clips shorter than two epsilons
that the single path always rejects), producing the very degenerate
slice the epsilon exists to prevent.
Extract the shared predicate canSplitElementAt and a selectSplittableElements
helper, and route both razor paths through them so the two stay consistent.
Adds unit coverage for the new helpers, including the regression where a
sub-epsilon clip with an interior split time must not be selected.
Co-authored-by: Carlos Alcaraz <193642530+calcarazgre646@users.noreply.github.com>
Wire the razor tool into Studio's timeline UI:
- B enters razor mode (crosshair cursor + red vertical guide line)
- Click any clip to split at the click position
- Shift+click splits all clips across every track at that time
- V or Escape exits razor mode
- Toolbar shows selection arrow / scissors toggle
Add useRazorSplit hook for split orchestration (HTML + GSAP mutation).
Add activeTool state to playerStore. Add preview reload after timeline
move/resize operations so the composition re-renders with updated timing.
Extract shared utilities to reduce duplication across timeline components:
- PlayheadIndicator: shared playhead rendering (was duplicated in
TimelineCanvas and TimelineEditorNotice)
- useContextMenuDismiss: outside-click/Escape dismiss pattern (was
duplicated in ClipContextMenu and KeyframeDiamondContextMenu)
- TimelineCallbacks: shared callback interfaces for drop and edit
operations (was duplicated in NLELayout and Timeline props)
- useTimelineZoom: consolidated zoom store selectors
- timelineElementSplit: shared canSplitElement, buildPatchTarget, and
readFileContent utilities
- gsapParser.test-helpers: shared test utilities for parser specs
