[2022117144]

Moving a referenced .flyde file in Explorer currently leaves the parent's file source pointing to its old location. This adds onWillRenameFiles handling for the current file-source format, including rebasing outgoing paths when a parent flow moves. Text edits join VS Code's rename operation and preserve YAML comments and dirty document content.

The change covers individual and folder moves, simultaneous swaps, nested inline nodes, and absolute references. Package sources are left unchanged; unreadable/invalid flows produce a warning. External shell/Git renames and legacy imports migration are outside this patch.

Validation:

• Strict TypeScript compilation of the new modules and tests.
• 12 path-remapping regression tests passed.
• Four scenarios passed in a real isolated VS Code 1.87.2 extension host: target move, parent move, folder move, and an unsaved parent edit.
• The full monorepo/webview build was not run: dependency resolution encountered connection resets. Details and reproduction steps are in vscode/docs/file-moves.md.

Short MP4 demo walkthrough — an animation of the recorded test cases, not a screen recording of the full Flyde UI.

AI-assisted contribution. No credentials or private backend configuration are included.

/claim #112