fix(call-omo-agent): enforce disabled_agents config (#1716)

## Summary
- Added disabled_agents parameter to createCallOmoAgent factory
- Check runs after ALLOWED_AGENTS validation, before agent execution
- Case-insensitive matching consistent with existing patterns
- Clear error message distinguishes 'disabled' from 'invalid agent type'
- Threaded disabledAgents config into tool factory from pluginConfig

## Changes
- tools.ts: Add disabledAgents parameter and validation check
- tool-registry.ts: Pass pluginConfig.disabled_agents to factory

src/plugin/tool-registry.ts

@@ -48,7 +48,7 @@ export function createToolRegistry(args: {
   const { ctx, pluginConfig, managers, skillContext, availableCategories } = args
 
   const backgroundTools = createBackgroundTools(managers.backgroundManager, ctx.client)
-  const callOmoAgent = createCallOmoAgent(ctx, managers.backgroundManager)
+  const callOmoAgent = createCallOmoAgent(ctx, managers.backgroundManager, pluginConfig.disabled_agents ?? [])
 
   const isMultimodalLookerEnabled = !(pluginConfig.disabled_agents ?? []).some(
     (agent) => agent.toLowerCase() === "multimodal-looker",