Add optional 'from' parameter to send_message

- Allow explicit sender role instead of auto-detection
- Fixes issue where process.cwd() doesn't match caller workspace
- Users can specify from: 'admin-dev', 'api-dev', or 'web-dev'
- Falls back to detectRole() if not provided

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/tools/builtin/messaging.ts

@@ -22,6 +22,7 @@ function detectRole(): string {
 // Schemas
 const SendMessageSchema = z.object({
   to: z.enum(['admin-dev', 'api-dev', 'web-dev']),
+  from: z.enum(['admin-dev', 'api-dev', 'web-dev']).optional(),
   subject: z.string(),
   message: z.string(),
   data: z.record(z.any()).optional(),
@@ -46,8 +47,8 @@ export class SendMessageTool extends ToolHandler<SendMessageInput, any> {
   }
 
   protected async handle(input: SendMessageInput, _context: ToolContext): Promise<any> {
-    const { to, subject, message, data } = input;
-    const from = detectRole();
+    const { to, from: explicitFrom, subject, message, data } = input;
+    const from = explicitFrom || detectRole();
 
     const payload = {
       from,