[refactor] Improve resize tracking composable documentation and test utilities

- Rename parameters in useVueElementTracking for clarity (appIdentifier, trackingType)
- Add comprehensive docstring with examples to prevent DOM attribute confusion
- Extract mountLGraphNode test utility to eliminate repetitive mock setup
- Add technical implementation notes documenting optimization decisions

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

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

CHANGES.md

@@ -0,0 +1,39 @@
+# Vue Node Resize Tracking Optimization
+
+## Summary
+
+Implemented centralized resize tracking system with O(1) element registration, single ResizeObserver traversal, and extensible ECS architecture to optimize Vue node bounds synchronization.
+
+## Changes
+
+- **What**: Centralized resize registry with single ResizeObserver, optimized math functions for bounds computation, extensible tracking system, DDD-compliant file organization
+- **Breaking**: Moved composable from `src/composables/` to `src/renderer/extensions/vueNodes/composables/` (DDD architecture)
+- **Dependencies**: None
+
+## Review Focus
+
+### Performance Optimizations
+- **Single ResizeObserver**: Replaced per-component observers with centralized registry to minimize browser reflow
+- **O(1) Element Access**: Map-based tracking configs eliminate linear searches across element types
+- **Single Traversal**: Batch processing groups updates by type in one ResizeObserver callback
+- **Optimized Math**: Union bounds computation uses incremental min/max instead of array operations
+
+### Architecture Decisions
+- **ECS Pattern**: Element-Component-System design allows tracking different element types (nodes, widgets, slots) with shared infrastructure
+- **Extensible Registry**: `trackingConfigs` Map enables adding new element types without core logic changes
+- **Data Attribute Strategy**: Uses configurable data attributes (e.g., `data-node-id`) for O(1) element identification vs DOM traversal
+
+### Technical Implementation
+- **Yjs Batch Optimization**: Removed race condition check in `batchUpdateNodeBounds` that could drop updates during concurrent transactions
+- **Null Safety**: Replaced never-null assertions with proper error handling and null checks
+- **Vue Lifecycle Integration**: Automatic cleanup on component unmount prevents memory leaks
+- **Type Safety**: Full TypeScript coverage with proper bounds interfaces
+
+### Testing Strategy
+- **Component-focused**: Uses Vue Test Utils for realistic DOM integration vs complex unit test mocking
+- **Utility Extraction**: Centralized test setup eliminates repetitive mock configuration
+- **Injection Mocking**: Proper Vue dependency injection setup for component isolation
+
+### Mathematical Optimizations
+- **Bounds Union**: `computeUnionBounds` uses streaming min/max calculation (O(n)) instead of coordinate array operations (O(n log n))
+- **Transform Calculations**: Leverages ResizeObserver's native `contentBoxSize` API for accurate dimensions without layout thrashing

src/renderer/extensions/vueNodes/components/LGraphNode.vue

@@ -112,7 +112,6 @@
 <script setup lang="ts">
 import { computed, inject, onErrorCaptured, ref, toRef, watch } from 'vue'
 
-// Import the VueNodeData type
 import type { VueNodeData } from '@/composables/graph/useGraphNodeManager'
 import { useErrorHandling } from '@/composables/useErrorHandling'
 import { LiteGraph } from '@/lib/litegraph/src/litegraph'