feat: add cross-milestone switching logic to mgw:run

[snipcodeit]

Summary

Before creating a worktree in mgw:run, detect if the issue belongs to a non-active GSD milestone. Route based on issue type: gsd:quick issues run in isolation (no ROADMAP.md needed), gsd:plan-phase issues warn and offer milestone switch.

Logic

1. Get issue's milestone from project.json
2. Compare milestone's gsd_milestone_id with active_gsd_milestone
3. If match: proceed normally
4. If mismatch + gsd:quick: proceed with note "Running in isolation"
5. If mismatch + gsd:plan-phase: warn "This issue belongs to milestone X but active GSD milestone is Y. Switch? (Y/N)"

Files

• commands/run.md — add cross-milestone detection block in validate_and_load step

GSD Route

gsd:quick

Depends On

• C1 (active_gsd_milestone must exist)

[snipcodeit]

MGW execution-complete · 2026-03-01T00:00:00Z
Milestone: v3 — Multi-Milestone Tracking | Phase 25: Cross-Milestone Operations

Implementation Complete

Implemented in commit c6bc557 on branch feat/mgw-gsd-architecture-repair.

Added cross-milestone detection block to commands/run.md (validate_and_load step): checks if the issue being run belongs to a different milestone than the currently active one. Quick-route issues get an isolation note; plan-phase issues trigger a switch/continue/abort prompt to prevent accidental cross-milestone contamination.

Part of PR #102.