Route in-band execution through the comprehensive tool dispatcher

The internal execute route used the bare server-tool router, which rejects
VFS tools with 'Unknown server tool: read/glob/grep' — so nearly every
background agent's first discovery call failed (102 in-band calls in one run,
dozens rejected). It now uses the relay's executeTool dispatcher: registered
handlers (VFS, function execute) with permission checks and param
normalization, falling back to the app tool router — the same surface
foreground execution gets.

apps/sim/app/api/copilot/tools/execute/route.ts

@@ -14,7 +14,8 @@ import {
 } from '@/lib/copilot/request/tools/resolved-secret-result'
 import { handleResourceSideEffects } from '@/lib/copilot/request/tools/resources'
 import type { ToolCallResult } from '@/lib/copilot/request/types'
-import { createServerToolHandler } from '@/lib/copilot/tools/registry/server-tool-adapter'
+import { ensureHandlersRegistered } from '@/lib/copilot/tool-executor'
+import { executeTool } from '@/lib/copilot/tool-executor/executor'
 import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
 import type { ResolvedSecretTraceRegistry } from '@/executor/utils/resolved-secret-trace-registry'
 
@@ -128,8 +129,12 @@ export const POST = withRouteHandler((request: NextRequest) =>
       }
 
       try {
-        const handler = createServerToolHandler(toolName)
-        const result = await handler(params, {
+        // The relay's comprehensive dispatcher: registry handlers (VFS
+        // glob/read/grep, function execute, ...) plus the server tool router
+        // fallback — the plain server-tool adapter alone rejects VFS tools
+        // with "Unknown server tool".
+        ensureHandlersRegistered()
+        const result = await executeTool(toolName, params, {
           userId,
           workflowId: workflowId ?? '',
           workspaceId,