feat: integrate workflow task results locally

[leynier]

Summary

• launch approved workflow tasks once in isolated managed attempts with frozen reviewed profiles and private context
• integrate committed results serially with durable Git receipts, conflict preservation, crash recovery and evidence-bound dependency release
• bind every successful workflow result to the exact clean task commit captured at completion
• reject prepared-result replay when the retained task worktree gains uncommitted changes
• keep workflow-owned acceptance and restart recovery authoritative across timeout races and terminal dispatch failures
• clear stale Board Attention when a reviewed same-task retry workspace supersedes a failed launch
• serialize task preparation with local integration and revalidate exact worktree state after the durable launch claim
• surface stalled workflow tasks instead of preserving a stale started launch phase
• settle stalled workflow launches into retained Attention state and require an explicit fresh attempt before redispatch
• retain frozen concurrency capacity for cancelled workers until host-confirmed teardown and durable settlement
• project Result Ready, Integrated, Conflict and Attention states into the global Run Board with explicit execution-workspace actions
• expand exact-revision desktop validation for workflow launch and native Git recovery on Linux, macOS and Windows

Validation

• current-head make rust-test (1441 CLI/host, 353 core and 191 native tests passed; 3 existing ignores)
• current-head workflow recovery suites (79 core and 65 CLI/host tests passed)
• implementation-head flutter test --coverage (3509 passed, 1 existing skipped)
• current-head flutter analyze
• current-head filtered Run Board/workflow unit, widget and golden regressions (34 passed)
• flutter test test/golden --no-pub (9 passed)
• dart format --set-exit-if-changed lib test integration_test tool
• Actionlint, max-lines ratchet and git diff --check

Visual evidence

Result Ready inspector at compact width and 150% text scale:

Run Board task states and inspector:

Risks

• worktrees isolate Git state, not the operating system
• interrupted or conflicting operations retain resources in Attention and require explicit recovery
• current-head hosted desktop builds and platform-native tests remain required before this draft is ready for review