Update vscode-rojo submodule reference and complete migration plan for path encoding

- Updated the vscode-rojo submodule to the latest commit.
- Marked all phases of the path encoding migration plan as completed, transitioning to a slugify and deduplication approach.
- Updated documentation to reflect changes in filename handling and metadata management.

.cursor/rules/src.mdc

@@ -68,10 +68,16 @@ Transforms files → `InstanceSnapshot`. Main entry: `snapshot_from_vfs()`
 pub struct InstanceContext {
     pub path_ignore_rules: Arc<Vec<PathIgnoreRule>>,
     pub sync_rules: Vec<SyncRule>,
-    pub decode_windows_invalid_chars: bool,  // Default: true
 }
 ```
 
+**Filename handling (syncback/two-way sync):**
+
+Instance names with forbidden filesystem chars (`<>:"/\|?*`) are handled by:
+1. `slugify_name()` -- replaces forbidden chars with `_` (pure, stateless)
+2. `deduplicate_name()` -- appends `~1`, `~2`, etc. on collision (stateful)
+3. Metadata `name` field -- stores the real instance name in `.meta.json5`/`.model.json5` when the slug differs
+
 ### 3. Commands (`src/cli/`)
 
 - `serve.rs` - Live sync with WebSocket