- Removed `#compactedChildStart` state, `compactable` segment field, and `#compactCommittedPrefix()` method, stopping the local-frame pruning of committed finalized rows.
- Post-finalize mutations now surface on every render via version tracking, instead of requiring a destructive replay to rehydrate the compacted block.
- Changed `print-mode.ts` to use `session.getLastAssistantMessage()` instead of array tail read, fixing access to terminal assistant messages after compaction removal.
TranscriptContainer gated committed-prefix compaction on version === undefined, so version-tracked AssistantMessageComponent history never compacted and every stream tick re-walked all N sealed blocks (depth-linear compose).
Compact fully-committed finalized blocks regardless of post-finalize version tracking: their rows are immutable native scrollback the terminal owns. A post-commit mutation no longer recommits on ordinary frames (no duplication) and rehydrates on the next destructive full replay (no loss). Adds the permanent bench/transcript-compose.bench.ts fixture; ratio(N5000/N500) drops 2.30 -> 0.90.
Fixes#5930
After #5239 compaction, a later render only fills segments from
#compactedChildStart, leaving undefined holes in the prefix. Iterating
those entries crashed when retiring IRC/ephemeral cards
(`segment2.component`). Guard undefined segment slots and cover the
sparse-hole path with a red/green regression.
- Added auto-sealing logic to `FinalizableBlock` to finalize displaceable snapshots when they enter the scrollback area.
- Updated TUI frame emission to publish committed rows and clamp them to segment bounds, ensuring accurate component updates.
- Introduced component tracking and cleanup in event controller tests to prevent resource leaks during finalization.
- Validated state transitions and post-emit synchronization through comprehensive new test suites for transcript and TUI components.
- Added comprehensive unit tests for `TranscriptContainer` to verify uncommitted block tracking.
- Created integration tests ensuring `AssistantMessageComponent` correctly streams thinking and answer content into scrollback.
- Added tests verifying that expanded tool evaluation output records rows correctly without duplication after settling.
- Updated `AssistantMessageComponent` test suite to cover table streaming scenarios in the unsettled tail.
- Replaced commit-based stability checks with a unified `isTranscriptBlockFinalized` tracking mechanism.
- Removed deprecated provisional rendering configuration and flags across tool and renderer interfaces.
- Standardized native scrollback boundary logic to pin at the first unfinalized block using settled row verification.
- Updated and refactored test suites to validate block finalization and settled row boundaries instead of deprecated commit stability methods.
- Replaced regex-based markdown detection with a stateful parser in `detectLiveReflowingMarkdown`.
- Correctly ignore table delimiters and mermaid markers when they appear inside fenced code blocks.
- Added tests to verify that code blocks containing markdown-like syntax do not prevent commit stability.
- Prevent object reference sharing between agent snapshots and stream events by deep-cloning tool-call arguments.
- Stabilize GFM tables and Mermaid diagrams during streaming by delaying transcript block commits until content finalization.
- Implement session resume safety to prevent crashes when working directories are missing.
- Add comprehensive test suites to verify streaming commit stability and immutable snapshot isolation.
- Added tail-only transcript rendering via `renderViewportTail`, stopping at `maxRows` and returning `EMPTY_TAIL`.
- Added `ViewportTailProvider`/`asViewportTailProvider` API and resize getters for viewport state.
- Implemented viewport-only painting during non-mux resize with deferred full repaint after settle.
- Added settle-resize helpers and coverage for deferred repaint timing and cancel paths.
- Added commit-stability signaling to transcript blocks and marked tool previews as unstable until expanded or finalized.
- Updated transcript scrollback promotion to derive live commit state only for blocks reporting commit-stable rows.
- Added tests ensuring provisional pending edit previews are never committed while durable live rows still promote after the stability window.
- Added transcript and assistant block version tracking for finalized segments.
- Changed committed block reuse logic to require prior finalization and same version.
- Fixed rerendering of committed finalized blocks when version values changed.
- Removed terminal risk mode toggles from config, terminal state collection, and render controllers.
- Dropped snapshot freezing, thaw tracking, and finalized-block replay in transcript rendering.
- Removed clear-on-shrink settings and initialization hooks from selector and interactive mode flows.
- Simplified render scheduling by using requestRender() without mutation flags or stream checkpoints.
- Added `isUserInterruptAbort` and `shouldRenderAbortReason` helpers so interrupt handling can distinguish Esc-based aborts from other abort reasons.
- Updated assistant transcript rendering to suppress the `Interrupted by user` line while continuing to show generic or other abort labels.
- Updated plan-review and transcript container tests to assert interrupted assistant messages no longer render the redundant interrupt line.
- Added optional `reason` parameters to `Agent.abort` and `AgentSession.abort` APIs.
- Passed abort reasons through interrupt flows into underlying agent cancellation.
- Replaced hard-coded abort text with `resolveAbortLabel` for streaming and replayed messages.
- Fell back to generic `Request was aborted` text when no abort reason was provided.
- Centralized transcript spacing by stripping blank edges and inserting separators.
- Removed per-component leading spacers and empty placeholders that added extra gaps.
- Introduced TranscriptBlock grouping so related outputs render as single transcript children.
- Updated transcript-related tests to validate one-row block separators and blank-line trimming.
- Shared immutable model registries and auth storage via beforeAll/afterAll.
- Swapped fixed-delay settle sleeps for predicate polling and signals.
- Stubbed network/timers to drop wall-clock waits in registry and history tests.
- Added resetDisplay invalidation tests and startup-timing breakdown lines.
- Cleared native scrollback on `omp`/`omp -c` so the resumed transcript no longer stacks on the prior run's welcome screen.
- Tracked assistant block finalization so aborted streaming messages stay repaintable when status rows land beneath them on ED3-risk terminals.
- Replaced bottom-most-block liveness with a finalization check so the live region spans every still-mutating block.
- Kept unfinalized tools repaintable when out-of-band inserts append finalized blocks below them.
- Recomputed blocks as they cross out of the live region to seal their final content.
- Added `NativeScrollbackLiveRegion` seam so components report the live suffix start.
- Stopped ED3-risk streaming from dropping sealed transcript rows above the live block.
- Appended newly sealed rows once while keeping the active tail deferred to checkpoint.
- Added NativeScrollbackLiveRegion seam reporting where a component's transient suffix begins.
- Pinned the live block and chrome below it out of native history during foreground streams on ED3-risk terminals.
- Consumed pending forced scrollback wipes while pinned to avoid yanking a scrolled-up reader (#1682).
- Tracked the previous live child in TranscriptContainer and forced a one-off recompute when a block leaves live status.
- Skipped snapshot reuse for that transitioning block so coalesced finalize-and-append frames seal transcript blocks at their final content.
- Added a regression test covering the stale-prefix freeze case on ED3-risk terminals and confirming the frozen block stays unchanged until thaw.
- Added assistant-message completion state and stable-line count reporting.
- Added transcript stable-row aggregation and snapshot replay to keep unstable rows out of scrollback.
- Added TUI stable scrollback boundary APIs and stable-prefix commit path.
- Added regression tests proving unstable rows stay out of scrollback until stabilized.
- Added TranscriptContainer that snapshots non-live blocks to avoid stale scrollback duplicates.
- Thawed snapshots at prompt-submit checkpoints for reconciliation.
- Repainted eager streaming tail on overflowing shrink to unfreeze UI (issue #1682).
Shawn Koh