fix(vscode): rewrite .flyde imports on file rename/move (#112)

[dukunline-cyber]

/claim #112

Closes #112.

Problem

When a file referenced by a .flyde flow is moved to a different folder (or when a .flyde flow itself is moved), the relative path stored in source: { type: file, data: ... } breaks and the import fails to resolve.

Reproduction matches the issue body: create a flow, import another flow, move either file -> import is broken until manually edited.

Fix

New module vscode/src/flydeImportRewriter.ts registers a vscode.workspace.onDidRenameFiles listener that handles both directions:

1. Moved file IS a .flyde flow -> rewrite each data: value inside the moved flow so the relative path resolves to the same absolute target it pointed at before the move.
2. Moved file is an IMPORTED target -> walk all .flyde files in the workspace (excluding node_modules) and rewrite any data: value whose resolved absolute path matches the old location.

The rewriter:

• Operates only on source blocks where type: file (leaves package and inline sources untouched).
• Edits only the data: line, preserving indentation, quoting style, and surrounding YAML so diffs stay minimal and YAML-valid.
• Uses POSIX-style ./relative paths to match the existing convention in the repo's sample flows.
• Is case-insensitive on win32 paths.
• Wraps every rewrite in try/catch so a single corrupt flow file can never crash the listener.

Wired up via 4-line patch in vscode/src/extension.ts (one import + one call inside activate).

Diff stats

• vscode/src/flydeImportRewriter.ts - new file, 176 lines
• vscode/src/extension.ts - +4 lines

Verification notes

• VSCode's onDidRenameFiles fires for both single-file renames and folder moves (folder moves emit one event per descendant), so folder-level reorganization is covered.
• The YAML walker is line-based and indentation-aware, so it tolerates the existing flow files in website/playground-examples/* and test-fixtures/.
• Listener is disposed automatically because the subscription is pushed onto context.subscriptions.

Happy to add unit tests around mutateFileSourceData if the maintainers want a follow-up.

[dukunline-cyber]

/claim #112

[dukunline-cyber]

Hi, just checking in — any feedback on this PR? Happy to address any changes needed.