feat(projman): add sprint lifecycle state machine via milestone metadata

- New skill: sprint-lifecycle.md defines states, transitions, and check protocol
- All sprint commands now check and set lifecycle state
- States tracked in milestone description metadata (Sprint/Planning, Sprint/Executing, Sprint/Reviewing)
- Out-of-order calls produce warnings with guidance
- --force override available for all lifecycle checks
- Added Sprint/* labels to label taxonomy documentation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/projman/commands/review.md

@@ -8,6 +8,7 @@ agent: code-reviewer
 ## Skills Required
 
 - skills/review-checklist.md
+- skills/sprint-lifecycle.md
 
 ## Purpose
 
@@ -19,6 +20,7 @@ Run `/review` before `/sprint-close` to catch issues.
 
 ## Workflow
 
+0. **Check Lifecycle State** - Execute `skills/sprint-lifecycle.md` check protocol. Expect `Sprint/Executing`. Set `Sprint/Reviewing` after review begins. Warn if in wrong state (allow with `--force`).
 1. **Determine Scope** - Sprint files or recent commits (`git diff --name-only HEAD~5`)
 2. **Read Files** - Use Read tool for each file in scope
 3. **Scan for Patterns** - Check each category from review checklist

plugins/projman/commands/sprint-close.md

@@ -13,6 +13,7 @@ agent: orchestrator
 - skills/rfc-workflow.md
 - skills/progress-tracking.md
 - skills/git-workflow.md
+- skills/sprint-lifecycle.md
 
 ## Purpose
 
@@ -26,6 +27,7 @@ Run `/sprint-close` when sprint work is complete.
 
 Execute the sprint close workflow:
 
+0. **Check Lifecycle State** - Execute `skills/sprint-lifecycle.md` check protocol. Expect `Sprint/Reviewing`. Clear all Sprint/* labels (return to idle) at the END of close workflow, after all other steps. Warn if in wrong state (allow with `--force`).
 1. **Review Sprint Completion** - Verify issues closed or moved to backlog
 2. **Capture Lessons Learned** - Interview user about challenges and insights
 3. **Tag for Discoverability** - Apply technology, component, and pattern tags

plugins/projman/commands/sprint-plan.md

@@ -18,6 +18,7 @@ agent: planner
 - skills/sprint-approval.md
 - skills/planning-workflow.md
 - skills/label-taxonomy/labels-reference.md
+- skills/sprint-lifecycle.md
 
 ## Purpose
 
@@ -35,6 +36,7 @@ Provide sprint goals as natural language input, or prepare input via:
 Execute the planning workflow as defined in `skills/planning-workflow.md`.
 
 **Key steps:**
+0. **Check Lifecycle State** - Execute `skills/sprint-lifecycle.md` check protocol. Expect idle state. Set `Sprint/Planning` after planning completes. Warn and stop if sprint is in another active state (unless `--force`).
 1. Run pre-planning validations (branch, repo org, labels)
 2. Detect input source (file, wiki, or conversation)
 3. Search relevant lessons learned

plugins/projman/commands/sprint-start.md

@@ -15,6 +15,7 @@ agent: orchestrator
 - skills/git-workflow.md
 - skills/progress-tracking.md
 - skills/runaway-detection.md
+- skills/sprint-lifecycle.md
 
 ## Purpose
 
@@ -31,7 +32,7 @@ Run `/sprint-start` when ready to begin executing a planned sprint.
 
 Execute the sprint start workflow:
 
-1. **Verify Sprint Approval** (required) - Check milestone for approval record. STOP if missing unless `--force` flag provided.
+1. **Verify Sprint Approval & Lifecycle State** (required) - Check milestone for approval record. STOP if missing unless `--force` flag provided. Also verify lifecycle state is `Sprint/Planning` per `skills/sprint-lifecycle.md`. Set `Sprint/Executing` after verification passes.
 2. **Detect Checkpoints** - Check for resume points from interrupted sessions
 3. **Fetch Sprint Issues** - Get open issues from milestone
 4. **Analyze Dependencies** - Use `get_execution_order` for parallel batches

plugins/projman/commands/sprint-status.md

@@ -9,6 +9,7 @@ description: Check current sprint progress, identify blockers, optionally genera
 - skills/mcp-tools-reference.md
 - skills/progress-tracking.md
 - skills/dependency-management.md
+- skills/sprint-lifecycle.md
 
 ## Purpose
 
@@ -23,6 +24,7 @@ Check current sprint progress, identify blockers, and show execution status. Opt
 
 ## Workflow
 
+0. **Display Lifecycle State** - Read current Sprint/* state from milestone description per `skills/sprint-lifecycle.md` and display in output header.
 1. **Fetch Sprint Issues** - Get all issues for current milestone
 2. **Calculate Progress** - Count completed vs total issues
 3. **Identify Active Tasks** - Find issues with `Status/In-Progress`