feat: PR lifecycle skill must detect and resolve merge conflicts before advancing stages

[diberry]

Problem

The pr-lifecycle skill (.squad/skills/pr-lifecycle/SKILL.md) advances PRs through label-driven stages but does not handle merge conflicts. When Ralph tries to rebase a PR at the squad:pr-dina-approved stage, conflicts can stall the pipeline silently.

Expected Behavior

Ralph should:

1. Detect conflicts before attempting rebase (check if branch can be cleanly rebased against dev)
2. Attempt auto-resolution for simple conflicts (e.g., .squad/ state files with union merge driver)
3. Report unresolvable conflicts by posting a comment on the PR listing the conflicting files
4. NOT advance the label if conflicts remain -- leave the current stage label in place
5. Add a squad:pr-conflict label so the conflict is visible in scans

Acceptance Criteria

• pr-lifecycle SKILL.md updated with conflict detection at each stage transition
• Ralph checks for conflicts before rebase (squad:pr-dina-approved stage)
• Conflicts are reported as PR comments listing affected files
• squad:pr-conflict label created and applied when conflicts found
• Auto-resolution attempted for known safe patterns (union merge files)
• PR does not advance stages while conflicts exist

Context

• PR lifecycle skill: .squad/skills/pr-lifecycle/SKILL.md
• Fork-first pipeline: .copilot/skills/diberry-squad-fork-first-pipeline/SKILL.md
• This affects all repos in the project-dina fleet that use the pr-lifecycle pipeline

Source: project-dina HQ session 2026-03-31

[github-actions]

📋 Assigned to FIDO (Quality Owner)

Issue: #130 — feat: PR lifecycle skill must detect and resolve merge conflicts before advancing stages

FIDO will pick this up in the next Copilot session.

For Copilot coding agent: If enabled, this issue will be worked automatically.
Otherwise, start a Copilot session and say:
FIDO, work on issue #130

[github-actions]

🏗️ Squad Triage — Flight (Lead)

Issue: #130 — feat: PR lifecycle skill must detect and resolve merge conflicts before advancing stages
Assigned to: Flight (Lead)
Reason: No specific domain match — assigned to Lead for further analysis

@copilot evaluation: 🔴 Not suitable — issue involves work outside the coding agent's capability profile.

Team roster:

• Flight (Lead) → label: squad:flight
• Procedures (Prompt Engineer) → label: squad:procedures
• EECOM (Core Dev) → label: squad:eecom
• FIDO (Quality Owner) → label: squad:fido
• PAO (DevRel) → label: squad:pao
• CAPCOM (SDK Expert) → label: squad:capcom
• CONTROL (TypeScript Engineer) → label: squad:control
• Surgeon (Release Manager) → label: squad:surgeon
• Booster (CI/CD Engineer) → label: squad:booster
• GNC (Node.js Runtime) → label: squad:gnc
• Network (Distribution) → label: squad:network
• RETRO (Security) → label: squad:retro
• INCO (CLI UX & Visual Design) → label: squad:inco
• GUIDO (VS Code Extension) → label: squad:guido
• Telemetry (Aspire & Observability) → label: squad:telemetry
• VOX (REPL & Interactive Shell) → label: squad:vox
• DSKY (TUI Engineer) → label: squad:dsky
• Sims (E2E Test Engineer) → label: squad:sims
• Handbook (SDK Usability) → label: squad:handbook
• Ralph (Work Monitor) → label: squad:ralph
• @copilot (Coding Agent) → label: squad:copilot

To reassign, remove the current squad:* label and add the correct one.

[github-actions]

⚠️ No squad member found matching label squad:archive. Check .squad/team.md (or .ai-team/team.md) for valid member names.