feat(projman): add visual output requirements to agents and commands

Add Visual Output sections to all projman files:
- 4 agent files with phase-specific headers (PLANNING, EXECUTION, CLOSING)
- 16 command files with appropriate headers

Headers use double-line box characters for projman branding:
- Planning phase: TARGET PLANNING
- Execution phase: LIGHTNING EXECUTION (+ progress block for orchestrator)
- Closing phase: FLAG CLOSING
- Setup commands: GEAR SETUP

Closes #273, #274

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

plugins/projman/commands/sprint-close.md

@@ -284,6 +284,22 @@ Would you like me to handle git operations?
 [Y/n]
 ```
 
+## Visual Output
+
+When executing this command, display the plugin header:
+
+```
+╔══════════════════════════════════════════════════════════════════╗
+║  📋 PROJMAN                                                      ║
+║  🏁 CLOSING                                                      ║
+║  [Sprint Name]                                                   ║
+╚══════════════════════════════════════════════════════════════════╝
+```
+
+Replace `[Sprint Name]` with the actual sprint/milestone name.
+
+Then proceed with the sprint close workflow.
+
 ## Getting Started
 
 Simply run `/sprint-close` when your sprint is complete. The orchestrator will guide you through: