fix(branch,workflow): branch agent state 유지 + workflow filter 유지 (T1~T4)

[hang-in]

요약

다모앙 커뮤니티 사용자 보고 2건 (frontend 한정):

1. branch/RT 전환 시 agent 활성화(engine/model/persona) 초기화 — shadow conv engine 상속 부재
2. workflow filter 가 plan status 변경 후 "plan-check" 으로 강제 리셋

• Plan: docs/plans/branchAgentStateAndFilterPersistPlan_2026-05-29.md
• Handoff: docs/prompts/branchAgentStateAndFilterPersistDeveloperHandoff_2026-05-29.md

Task 별 변경

Task	파일	변경
T1	src/stores/slices/branchSlice.ts	openBranchStream 에서 set() 이후 부모 conv engine 을 shadow conv 키(branch:<branchId>)로 상속. 부모 미설정 시 상속 안 함 (INV-BAF-2)
T2	src/stores/slices/branchSlice.ts	!getConversationEngine(branchConvId) 조건으로 첫 진입만 상속 — 재진입 시 사용자가 branch 안에서 바꾼 engine 보존
T3	src/components/tunaflow/CenterPanel.tsx	onStatusChanged 에서 setActiveStage("plan-check") 제거. setPlanRefreshKey 유지. onPhaseChanged → PHASE_TO_STAGE 자동 전환은 보존 (INV-BAF-4)
T4	src/tests/branchAgentStateAndFilterPersist.test.tsx	engine 상속/재진입 보존/부모-null 보존 (실제 store action 구동) + filter 유지/phase 자동전환 (CenterPanel render) — 신규 5 test

변경 통계: 3 files, +232 / -1 (T4 테스트 214줄 포함). 실 로직 변경은 branchSlice +5줄, CenterPanel -1줄.

Verification

• npx tsc --noEmit — PASS (0 error)
• npx vitest run — 496 passed (baseline 491 + T4 5건)
• cargo check — Finished, 0 변경 (Rust 영역 미수정)

회귀 가드 (handoff §6)

• git diff main -- src-tauri/ → 0줄 (Rust 미변경)
• git diff main -- NewMessageInput.tsx → 0줄 (restore effect 보존)
• CenterPanel diff: setActiveStage("plan-check") 한 줄 제거만 — onPhaseChanged 핸들러 + PHASE_TO_STAGE 매핑 byte-identical (보존)
• branchSlice: if (parentEngine && !get().getConversationEngine(branchConvId)) 상속 가드 확인

RT participants scope 명시

본 PR 은 engine 상속만 다룸. RT config (participants/mode, DB rt_config) 상속은 별 이슈 — 사용자 보고의 "agent 활성화" 가 engine selector 면 본 PR 로 해결, RT participants 면 별 plan 으로 escalate (Non-goal 명시).

환경 메모

worktree 에 node_modules / src-tauri/binaries 부재 → main repo symlink 사용 (커밋 영향 없음, 미스테이지).

🤖 Generated with Claude Code

[gemini-code-assist]

Code Review

This pull request resolves issues with workflow filter persistence and branch conversation state. Specifically, it prevents resetting the active workflow filter to 'plan-check' upon status changes in CenterPanel, and inherits the parent conversation's engine configuration when entering a branch conversation in branchSlice. Comprehensive tests have also been added to verify these behaviors. The reviewer recommends shallow copying the inherited parentEngine object to prevent potential shared-state mutation bugs.

[gemini-code-assist]

To prevent accidental shared-state mutation bugs, it is highly recommended to shallow copy the parentEngine object when inheriting it for the branch conversation. In state management libraries like Zustand, sharing the same object reference across multiple keys can lead to unexpected side effects if any part of the application mutates the state object directly.

Suggested change

	const parentEngine = get().getConversationEngine(selectedConversationId);
	if (parentEngine && !get().getConversationEngine(branchConvId)) {
	get().saveConversationEngine(branchConvId, parentEngine);
	}
	const parentEngine = get().getConversationEngine(selectedConversationId);
	if (parentEngine && !get().getConversationEngine(branchConvId)) {
	get().saveConversationEngine(branchConvId, { ...parentEngine });
	}