Release Notes 0.5.21

Summary

Release 0.5.21 packages the current runtime refresh as a publishable build. The codebase changes include the shared turn kernel, metadata-driven tool scheduling, normalized orchestration graph, typed worker roles, stricter verification, semantic batch summaries, the layered permission engine, the new session checklist primitive, and the UI/completion updates that surface them.

New Features

• Shared TurnKernel for steps, follow-ups, subagents, and verification flows.
• Session-scoped checklist primitive in SessionRuntime with task_list_create, task_list_update, and task_list_list.
• Metadata-driven ToolScheduler with automatic batching for safe reads and scoped serialization for writes.
• Normalized orchestration graph engine for delegated work, workflow phases, and ACP-backed task state.
• Built-in worker roles: researcher, implementer, verifier, and synthesizer.
• Stricter verification runtime with verdict/report output.
• Semantic tool-batch summaries surfaced in timeline and completion projections.
• Layered permission engine with explicit modes, rule sources, and workspace-rule management.

Enhancements

• Completion UI now carries richer terminal text from result summaries, semantic summaries, and verifier output.
• Right-panel task details now surface a read-only ordered session checklist plus a verification reminder banner when the runtime raises one.
• Follow-up messages remain visible in task timelines, including orphaned follow-ups handled after a main task completes.
• Screenshot-heavy visual refinement loops render more compactly in summary mode.
• Renderer surfaces were updated across the main content view, CLI frame, dispatched agents panel, and task event compatibility logic.
• Mission Control, task detail views, gateway relays, cron exports, and supervisor notifications consume the richer completion payload.
• Settings now includes a permission panel for default mode, profile rules, and workspace-local rule browsing/removal.

Fixes

• Fixed terminal-state divergence between task events and the task row for follow-up completion paths.
• Fixed a late resume race where approval-driven resume handling could overwrite a freshly completed task row back to executing.
• Fixed visibility for orphaned follow-up prompts in the timeline.
• Reduced noisy screenshot rendering during iterative canvas work.

Docs

• Updated the README, release index, and release note references to point at 0.5.21.
• Added a session note describing the runtime migration work completed in this cycle.

Internal / Runtime Changes

• Shared turn ownership now lives in the runtime kernel.
• SessionRuntime now owns the session checklist bucket, validation, verification-nudge logic, and replayable checklist events.
• Permission decisions now flow through a layered permission engine with session, workspace, profile, and compatibility rule sources.
• Tool batching, transcript normalization, and ordered tool-result handling are centralized.
• Delegated work is graph-backed across child tasks, workflow phases, collaborative teams, and ACP.
• Verification now uses a dedicated read-only worker role and verdict-based completion semantics.
• Tool-batch summaries are generated once per scheduler batch and attached to projections.
• ACP and control-plane task handlers now project delegated work from the orchestration graph instead of treating it as a separate runtime.
• Mailbox and inbox flows were tightened alongside their related tests so task completion and follow-up handoff paths stay consistent.
• Debug runtime and debug-mode orchestration were added for richer inspection of long-running sessions.
• Resume paths now re-read canonical persisted task state before writing executing, so terminal rows cannot be reopened by stale renderer or approval flow timing.
• ACpx runtime runner changes now route child execution through the same delegated-work primitives as the rest of the runtime.
• Content-builder and runtime helper modules were expanded to support the new execution, orchestration, and projection paths.
• Tool policy, search, middleware, handler registry, and envelope plumbing were updated to support the new scheduler and runtime contracts.
• Shared types, detection, sanitization, and timeline-event contracts were updated to match the new history and projection model.
• Renderer updates span debug, session, timeline, and completion surfaces so the new runtime state is visible end to end.
• The permission settings surface and workspace-rule management panel expose workspace-local policy state directly in the desktop UI.

Test / Build Changes

• Expanded unit coverage for the turn kernel, scheduler, orchestration graph, worker roles, verification, and completion projections.
• Improved build and packaging flow for the macOS release bundle.
• Release packaging now emits 0.5.21 artifact names and version metadata.
• A large test expansion landed across runtime, ACP, inbox/mailbox, debug, renderer, and release/build paths to cover the new subsystem wiring.
• Build and packaging scripts were updated alongside refreshed branding assets so the release artifacts and UI assets stay aligned.

Upgrade Notes

• Tasks resumed from older snapshots continue to work because runtime restore still falls back to legacy conversationHistory payloads and rewrites them to session_runtime_v2 on the next checkpoint.
• Execution-style tasks now have access to the session checklist primitive and its advisory verification nudge.
• Approval-driven or follow-up-driven resumes no longer risk reopening a task that has already reached a terminal state.