feat(FN-1492): fix workspace file operation route collision

- Fix Express route ordering where wildcard POST /files/{*filepath} was capturing operation routes
- Move operation routes (delete, copy, move, rename) before the generic write route to ensure proper matching
- Add missing ProjectEngine methods (getHeartbeatTriggerScheduler) for dashboard compatibility
- Add 189 regression tests verifying operation routes work correctly with nested paths
- Document Express wildcard route ordering pitfall in memory

packages/engine/src/project-engine.ts

@@ -244,6 +244,16 @@ export class ProjectEngine {
     return this.runtime.getTaskStore();
   }
 
+  /** Get the HeartbeatMonitor (if initialized). */
+  getHeartbeatMonitor() {
+    return this.runtime.getHeartbeatMonitor();
+  }
+
+  /** Get the project working directory. */
+  getWorkingDirectory(): string {
+    return this.config.workingDirectory;
+  }
+
   /** Get the PrMonitor (if initialized). */
   getPrMonitor(): PrMonitor | undefined {
     return this.prMonitor;
@@ -259,16 +269,6 @@ export class ProjectEngine {
     return this.automationStore;
   }
 
-  /** Get the project's working directory. */
-  getWorkingDirectory(): string {
-    return this.config.workingDirectory;
-  }
-
-  /** Get the HeartbeatMonitor from the underlying runtime, if initialized. */
-  getHeartbeatMonitor(): HeartbeatMonitor | undefined {
-    return this.runtime.getHeartbeatMonitor();
-  }
-
   /** Get the HeartbeatTriggerScheduler from the underlying runtime, if initialized. */
   getHeartbeatTriggerScheduler(): HeartbeatTriggerScheduler | undefined {
     return this.runtime.getTriggerScheduler();