fn-16-ugn.2 Update plan-sync agent for dry-run support

fn-16-ugn.2 Update plan-sync agent for dry-run support

Overview

Update the existing plan-sync agent to support a DRY_RUN mode where it reports proposed changes without actually editing files.

Context

• Agent file: plugins/flow-next/agents/plan-sync.md
• This agent is spawned by both:
  • /flow-next:work (auto-trigger in phases.md step 3e)
  • /flow-next:sync (new manual trigger from fn-16-ugn.1)

Changes Required

1. Add DRY_RUN Input

In the "Input from prompt" section, add:

- `DRY_RUN` - "true" or "false" (optional, defaults to false)

2. Modify Phase 5 (Update Affected Tasks)

Current behavior edits files unconditionally. Add dry-run handling:

## Phase 5: Update Affected Tasks

**If DRY_RUN is "true":**
Report what would be changed without using Edit tool:

Would update:

• fn-1.3: Change UserAuth.login() → authService.authenticate()
• fn-1.5: Change return type boolean → AuthResult

Do NOT use Edit tool. Skip to Phase 6.

**If DRY_RUN is "false" or not set:**
For each affected downstream task, edit only the stale references:
[...existing edit logic...]

3. Modify Phase 6 (Return Summary)

Update the summary format to indicate dry-run mode:

## Phase 6: Return Summary

**If DRY_RUN:**

Drift detected: yes

• fn-1.2 used authService singleton instead of UserAuth class

Would update (DRY RUN):

• fn-1.3: Change references from UserAuth.login() to authService.authenticate()
• fn-1.4: Update expected return type from boolean to AuthResult

No files modified.

**If not DRY_RUN:**
[...existing summary format...]

Key Points

• Don't break existing auto-trigger behavior (DRY_RUN defaults to false)
• Dry-run should still do full analysis (phases 1-4)
• Only phase 5 (Edit) and phase 6 (summary) change behavior
• Keep the same detailed reporting in dry-run mode

Acceptance

• DRY_RUN=true prevents Edit tool usage
• DRY_RUN=true reports proposed changes clearly
• DRY_RUN=false or missing works exactly as before (no regression)
• Summary clearly indicates dry-run mode when active

Done summary

Added DRY_RUN parameter to plan-sync agent. Phase 5 skips Edit tool when dry-run, Phase 6 shows "Would update (DRY RUN)" format with "No files modified" footer.

Evidence

• Commits: 05e024af578e2d4200923574083e74e56813876b
• Tests: smoke_test.sh
• PRs:

References

• Agent file: plugins/flow-next/agents/plan-sync.md
• Epic spec: .flow/specs/fn-16-ugn.md