Four tightly-scoped hot-path fixes covering the highest-impact items in the
reporter's CPU profile (13.1 s profiled / 30 s window):
1. `event-controller.ts:handleEvent` no longer fires a blanket
`statusLine.invalidate() + ui.requestRender()` before every session event.
The pre-render was a leftover from #4145 when `updateEditorTopBorder()`
still eagerly rebuilt the border; the lazy provider added in #4145 made
it redundant. It fired on every `message_update`/`tool_execution_update`
during streaming — the pre-render's frame ran while the handler was
awaiting, then the handler's own `requestRender` scheduled a second
identical frame. Every handler that mutates visible state already calls
`requestRender()`.
2. `shimmer.ts:shimmerSegments` iterates the segment string in place instead
of building a code-point array with `Array.from(seg.text)` every animation
frame. Runs of same-tier chars are emitted via a single `slice` per run
rather than accumulating into `runBuf`. Surrogate pairs stay atomic — the
code-point index still advances by 1 per emoji. Microbench over 30k
frames: 45 ms → 18 ms (2.53x), allocation rate down from ~N-per-frame to
a handful per frame. New tests cover mixed BMP+surrogate and all-emoji
inputs. `Array.from` was the #1 self-time hotspot in the reporter's
profile at 10.2%.
3. `Markdown.setText` gains an equality guard mirroring `Text.setText`
(returns `false` when `text === #text`). Providers re-emit identical text
on ticks with no delta (throttled frames, reconciled tool-execution
updates); each of those now short-circuits instead of dropping
`#cachedLines` and forcing a full lex + wrap on the accumulated paragraph
(the reporter's #3 hotspot at 8.4%). New test asserts render-reference
stability + return-value semantics.
4. `SPINNER_RENDER_INTERVAL_MS` aligned with `SPINNER_GLYPH_ADVANCE_MS`
(both 80 ms). The previous 33 ms cadence emitted ~2.4 paints per glyph
step; the differential-output dedup only skips the write, not the
compose walk. Visually identical (glyph advance was already 12.5fps),
halves paints during tool execution.
Skipped (out of scope for a bug fix, deserve dedicated PRs):
- Freezing streaming prefix on single `\n` boundaries — correctness-bound
to `\n\n` block separators (CommonMark loose-list continuation).
- Compose-phase idle gate + adaptive-backpressure moving-average — need a
component-level dirty flag; the 200 ms cap in `#scheduleRender` was set
for a reason (#4145 tail-latency guard).
Tests updated: two IRC-expiry tests in event-controller-message-start.test.ts
that were asserting the pre-render's second `requestRender` call now expect
one.
Fixes#4353
- Added `typeof theme === "undefined"` guards to all four theme getters.
- Fallbacks return a usable plain-ASCII or plain-text theme instead of crashing.
- Added a pre-init test asserting the getters never throw.
- Added a setup-system-deps action with preloaded-runner guards and apt fallbacks.
- Updated CI workflows to download Linux x64 native artifacts and gate on native job success.
- Renamed coding-agent fast mode to singleton in scripts and test partitioning logic.
- Added settings test-state begin/restore helpers with recursive cleanup in affected tests.
- Added `handleUsageResetCommand` support to list and redeem usage reset credits.
- Refactored `/usage` into `show` and `reset` subcommands and removed `/reset-usage`.
- Handled ACP/TUI `/usage` flows so `show` reports usage and `reset` redeems credits.
- Kept selected theme setting values dirty-colored while selected in the UI list.
- Reworked classic and KITT shimmer intensity math to drive the scan head by a constant 30 cells/second.
- Introduced length-aware travel periods for classic padding and KITT ping-pong motion while removing the prior fixed-duration phase helpers.
- Updated shimmer tests to validate crest movement stays within one cell per 30fps frame and is consistent across text lengths.
- Synchronized shimmer progression by switching `shimmer.ts` to a shared 2-second phase sweep, with crest/head position interpolated across the full visible span.
- Updated classic and KITT intensity calculations so shimmer starts at index 0 and reaches index length-1 together for any task row length.
- Adjusted shimmer tests to assert crest boundary and phase alignment behavior across short and long strings.
- Cached setting path segments and memoized `Settings.get()` results, clearing caches on updates.
- Triggered session-name and session-accent callbacks only when effective values changed, with error-safe dispatch.
- Memoized status-line and interactive accent resolution with cache invalidation on settings/theme/session changes.
- Added regression tests for keybinding precedence, status-line, settings, and accent cache behavior.
- Loading message rendering now derived session-specific accent colors and applied them to shimmer output when a session name was available.
- Shimmer palettes were updated to accept raw ANSI color values as well as theme color names during compilation.
- A unit test was added to confirm shimmer text rendered with a supplied ANSI crest color.
roboomp