feat(plugins): add Visual Output headers to all other plugin commands

Add single-line visual headers to 66 command files across 10 plugins:
- clarity-assist (2 commands): 💬
- claude-config-maintainer (5 commands): ⚙️
- cmdb-assistant (11 commands): 🖥️
- code-sentinel (3 commands): 🔒
- contract-validator (5 commands): ✅
- data-platform (10 commands): 📊
- doc-guardian (5 commands): 📝
- git-flow (8 commands): 🔀
- pr-review (7 commands): 🔍
- viz-platform (10 commands): 🎨

Each command now displays a consistent header at execution start:
┌────────────────────────────────────────────────────────────────┐
│  [icon] PLUGIN-NAME · Command Description                       │
└────────────────────────────────────────────────────────────────┘

Addresses #275 (other plugin commands visual output)

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

plugins/contract-validator/commands/check-agent.md

@@ -1,5 +1,17 @@
 # /check-agent - Validate Agent Definition
 
+## Visual Output
+
+When executing this command, display the plugin header:
+
+```
+┌──────────────────────────────────────────────────────────────────┐
+│  ✅ CONTRACT-VALIDATOR · Agent Check                              │
+└──────────────────────────────────────────────────────────────────┘
+```
+
+Then proceed with the validation.
+
 Validate a single agent's tool references and data flow.
 
 ## Usage

plugins/contract-validator/commands/dependency-graph.md

@@ -1,5 +1,17 @@
 # /dependency-graph - Generate Dependency Visualization
 
+## Visual Output
+
+When executing this command, display the plugin header:
+
+```
+┌──────────────────────────────────────────────────────────────────┐
+│  ✅ CONTRACT-VALIDATOR · Dependency Graph                         │
+└──────────────────────────────────────────────────────────────────┘
+```
+
+Then proceed with the visualization.
+
 Generate a Mermaid flowchart showing plugin dependencies, data flows, and tool relationships.
 
 ## Usage

plugins/contract-validator/commands/initial-setup.md

@@ -4,6 +4,18 @@ description: Interactive setup wizard for contract-validator plugin - verifies M
 
 # Contract-Validator Setup Wizard
 
+## Visual Output
+
+When executing this command, display the plugin header:
+
+```
+┌──────────────────────────────────────────────────────────────────┐
+│  ✅ CONTRACT-VALIDATOR · Setup Wizard                             │
+└──────────────────────────────────────────────────────────────────┘
+```
+
+Then proceed with the setup.
+
 This command sets up the contract-validator plugin for cross-plugin compatibility validation.
 
 ## Important Context

plugins/contract-validator/commands/list-interfaces.md

@@ -1,5 +1,17 @@
 # /list-interfaces - Show Plugin Interfaces
 
+## Visual Output
+
+When executing this command, display the plugin header:
+
+```
+┌──────────────────────────────────────────────────────────────────┐
+│  ✅ CONTRACT-VALIDATOR · List Interfaces                         │
+└──────────────────────────────────────────────────────────────────┘
+```
+
+Then proceed with the interface listing.
+
 Display what each plugin in the marketplace produces and accepts.
 
 ## Usage

plugins/contract-validator/commands/validate-contracts.md

@@ -1,5 +1,17 @@
 # /validate-contracts - Full Contract Validation
 
+## Visual Output
+
+When executing this command, display the plugin header:
+
+```
+┌──────────────────────────────────────────────────────────────────┐
+│  ✅ CONTRACT-VALIDATOR · Full Validation                         │
+└──────────────────────────────────────────────────────────────────┘
+```
+
+Then proceed with the validation.
+
 Run comprehensive cross-plugin compatibility validation for the entire marketplace.
 
 ## Usage