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-diagram.md

@@ -178,3 +178,16 @@ flowchart LR
 
 Open: 16 | In Progress: 1 | Completed: 1
 ```
+
+## Visual Output
+
+When executing this command, display the plugin header:
+
+```
+╔══════════════════════════════════════════════════════════════════╗
+║  📋 PROJMAN                                                      ║
+║  Sprint Diagram                                                  ║
+╚══════════════════════════════════════════════════════════════════╝
+```
+
+Then proceed to generate the diagram.