fix(plugin): prefix commands with core: namespace to avoid clashes

/dispatch → /core:dispatch, /status → /core:status, etc.
Prevents collision with built-in Claude commands.

Co-Authored-By: Virgil <virgil@lethean.io>

claude/code/commands/dispatch.md

@@ -1,5 +1,5 @@
 ---
-name: dispatch
+name: core:dispatch
 description: Dispatch a subagent to work on a task in a sandboxed workspace
 arguments:
   - name: repo

claude/code/commands/recall.md

@@ -1,5 +1,5 @@
 ---
-name: recall
+name: core:recall
 description: Search OpenBrain for memories and context
 arguments:
   - name: query

claude/code/commands/remember.md

@@ -1,5 +1,5 @@
 ---
-name: remember
+name: core:remember
 description: Save a fact or decision to context for persistence across compacts
 args: <fact to remember>
 ---

claude/code/commands/scan.md

@@ -1,5 +1,5 @@
 ---
-name: scan
+name: core:scan
 description: Scan Forge repos for open issues with actionable labels (agentic, help-wanted, bug)
 arguments:
   - name: org

claude/code/commands/status.md

@@ -1,5 +1,5 @@
 ---
-name: status
+name: core:status
 description: Show status of all agent workspaces (running, completed, blocked, failed)
 ---