Timer-driven reveal and spinner ticks (streaming reveal, tool-args reveal,
tool-execution spinner, todo strike animation) now hand the changed
component to `TUI.requestComponentRender(component)` instead of forcing a
full-tree render at 30fps. Every other root subtree reuses its previous
frame rows, cutting the Box/Container tree walk out of the compose
pipeline while the transcript grows.
Shimmer:
- Intern the working-message palette per accent (WeakMap-keyed) so the
Symbol-slot compiled-ANSI cache in `shimmerSegments.compile` actually
hits between frames — the fresh palette literal in `renderWorkingMessage`
guaranteed a per-tick miss.
- Add an `activeBand` fast-path: outside the sweep window the intensity
is guaranteed zero, so those code points coalesce into a single low-tier
run without running `intensityFn` or `tierFor`. On the typical ~60-char
working message the classic band is 12 cells wide, so ~80% of the per-char
loop disappears.
Widen `ToolExecutionHandle` to extend `Component` (matches every
concrete impl — `ToolExecutionComponent`, `ReadToolGroupComponent` —
which already extend `Container`) so the reveal controller callback
sites are type-checked.
Fixes#4377
roboomp
31ac7e27eb