feat: workspace panel visual overhaul, perf optimizations, remove kernel base addresses

Workspace panel:
- Custom WorkspaceDelegate: struct names bright, metadata dimmed, child types in teal
- Search box: monospace font, search icon, bordered with focus highlight
- Selection: accent bar, all fonts synced to 10pt monospace
- Remove rebuildWorkspaceModel from visibilityChanged (fixes double-click refresh)
- Incremental sync (syncProjectExplorer) preserves tree expansion state

Performance:
- childrenOf() O(1) via cached parent→children hash map
- Debounced workspace rebuilds (50ms coalesce)
- Pre-reserve node vector in NodeTree::fromJson
- Benchmark suite (bench_project)

Data:
- Remove kernel baseAddress from Vergilius/WinSDK examples (default to 0x400000)

src/examples/Vergilius_25H2.rcx

@@ -1,5 +1,4 @@
 {
-    "baseAddress": "FFFFF80000000000",
     "nextId": "20010",
     "nodes": [
         {

src/examples/WinSDK.rcx

@@ -1,5 +1,4 @@
 {
-    "baseAddress": "fffff80000000000",
     "nextId": "18212",
     "nodes": [
         {