feat: add event-driven group membership updates on insert/delete/move

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/lib/components/flows/map/FlowModuleSchemaMap.svelte

@@ -54,6 +54,7 @@
 	} from '../agentToolUtils'
 	import { loadFlowModuleState } from '../flowStateUtils.svelte'
 	import { getNoteEditorContext } from '$lib/components/graph/noteEditor.svelte'
+	import { getGroupEditorContext } from '$lib/components/graph/groupEditor.svelte'
 
 	interface Props {
 		sidebarSize?: number | undefined
@@ -125,6 +126,7 @@
 
 	// Get NoteEditor context for note position updates
 	const noteEditorContext = getNoteEditorContext()
+	const groupEditorContext = getGroupEditorContext()
 
 	$effect(() => {
 		if (!moveManager.movingModuleId) return
@@ -569,6 +571,7 @@
 						selectNextId(id)
 						removeAtId(flowStore.val.value.modules, id)
 					}
+					groupEditorContext?.groupEditor.removeNode(id)
 					refreshStateStore(flowStore)
 					onDelete?.(id)
 					delete flowStateStore.val[id]
@@ -629,6 +632,11 @@
 								}
 								targetModules.splice(insertIndex, 0, ...removedModules)
 								selectionManager.selectByIds(removedModules.map((m) => m.id))
+								for (const m of removedModules) {
+									groupEditorContext?.groupEditor.handleNodeMoved(
+										m.id, detail.sourceId, detail.targetId
+									)
+								}
 							} else {
 								let indexToRemove = originalModules.findIndex((m) => moveManager.movingModuleId == m.id)
 								let [removedModule] = originalModules.splice(indexToRemove, 1)
@@ -639,6 +647,9 @@
 								}
 								targetModules.splice(insertIndex, 0, removedModule)
 								selectionManager.selectId(removedModule.id)
+								groupEditorContext?.groupEditor.handleNodeMoved(
+									removedModule.id, detail.sourceId, detail.targetId
+								)
 							}
 							moveManager.clearMoving()
 						} else {
@@ -676,6 +687,7 @@
 									toolKind
 								)
 								const id = targetModules[index].id
+								groupEditorContext?.groupEditor.addInsertedNode(id, detail.sourceId, detail.targetId)
 								selectionManager.selectId(id)
 
 								if (detail.inlineScript?.instructions) {

frontend/src/lib/components/graph/groupEditor.svelte.ts

@@ -195,6 +195,55 @@ export class GroupEditor {
 	isAvailable(): boolean {
 		return !!this.flowStore.val.value
 	}
+
+	/** Remove a deleted node from all groups. Removes empty groups. */
+	removeNode(nodeId: string): void {
+		const groups = this.getGroups()
+		let changed = false
+		for (const group of groups) {
+			const idx = group.module_ids.indexOf(nodeId)
+			if (idx !== -1) {
+				group.module_ids.splice(idx, 1)
+				changed = true
+			}
+		}
+		if (changed) {
+			this.setGroups(groups.filter((g) => g.module_ids.length > 0))
+		}
+	}
+
+	/** Add a newly inserted node to the group that contains both its neighbors. */
+	addInsertedNode(newNodeId: string, sourceId?: string, targetId?: string): void {
+		if (!sourceId || !targetId) return
+		const groups = this.getGroups()
+		for (const group of groups) {
+			if (group.module_ids.includes(sourceId) && group.module_ids.includes(targetId)) {
+				group.module_ids.push(newNodeId)
+				this.setGroups(groups)
+				return
+			}
+		}
+	}
+
+	/** Handle a node that was moved to a new position in the flow. */
+	handleNodeMoved(movedId: string, sourceId?: string, targetId?: string): void {
+		const groups = this.getGroups()
+		const currentGroup = groups.find((g) => g.module_ids.includes(movedId))
+
+		if (currentGroup) {
+			// Was in a group — only keep if BOTH neighbors are in the same group
+			const sourceInGroup = sourceId ? currentGroup.module_ids.includes(sourceId) : false
+			const targetInGroup = targetId ? currentGroup.module_ids.includes(targetId) : false
+			if (!(sourceInGroup && targetInGroup)) {
+				// Moved to boundary or outside the group — remove
+				currentGroup.module_ids = currentGroup.module_ids.filter((id) => id !== movedId)
+				this.setGroups(groups.filter((g) => g.module_ids.length > 0))
+			}
+		} else {
+			// Wasn't in a group — check if moved into one
+			this.addInsertedNode(movedId, sourceId, targetId)
+		}
+	}
 }
 
 export type GroupEditorContext = {