refactor: update internal command references in all plugin files

Updated:
- projman: 4 commands + 4 skills + integration snippet
- git-flow: 4 commands + 3 skills + integration snippet
- pr-review: 1 command cross-reference
- cmdb-assistant: 1 command + 1 skill
- data-platform: 8 commands + integration snippet
- viz-platform: 11 commands + integration snippet
- contract-validator: 1 command + 1 skill + 1 agent

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

plugins/data-platform/commands/data-explain.md

@@ -1,4 +1,4 @@
-# /explain - dbt Model Explanation
+# /data-explain - dbt Model Explanation
 
 ## Skills to Load
 - skills/dbt-workflow.md
@@ -13,7 +13,7 @@ Display header: `DATA-PLATFORM - Model Explanation`
 ## Usage
 
 ```
-/explain <model_name>
+/data-explain <model_name>
 ```
 
 ## Workflow
@@ -26,8 +26,8 @@ Display header: `DATA-PLATFORM - Model Explanation`
 ## Examples
 
 ```
-/explain dim_customers
-/explain fct_orders
+/data-explain dim_customers
+/data-explain fct_orders
 ```
 
 ## Required MCP Tools