fix: stabilize maintenance flow run/resume and procedural scrolling

frontend/src/lib/routing.ts

@@ -5,7 +5,7 @@
  */
 
 /**
- * Get the navigation path for starting or resuming a tree/session.
+ * Get the default navigation path for starting a flow from the library.
  */
 export function getTreeNavigatePath(
   treeId: string,
@@ -20,6 +20,20 @@ export function getTreeNavigatePath(
   return `/trees/${treeId}/navigate`
 }
 
+/**
+ * Get the navigation path for resuming an existing session.
+ * Maintenance and procedural sessions both resume in procedural navigation.
+ */
+export function getSessionResumePath(
+  treeId: string,
+  treeType?: string
+): string {
+  if (treeType === 'procedural' || treeType === 'maintenance') {
+    return `/flows/${treeId}/navigate`
+  }
+  return `/trees/${treeId}/navigate`
+}
+
 /**
  * Get the editor path for a tree.
  */