perf(move-file): batch import specifier rewrites

[LayZeeDK]

Summary

Collect and apply import specifier rewrites in batches so each touched file is parsed and modified only once per generator run.

Proposed Solution

interface ImportUpdate {
  filePath: string;
  oldSpecifier: string;
  newSpecifier: string;
}

const pendingImportUpdates = new Map<string, ImportUpdate[]>();

function scheduleImportUpdate(update: ImportUpdate): void {
  const updates = pendingImportUpdates.get(update.filePath) || [];
  updates.push(update);
  pendingImportUpdates.set(update.filePath, updates);
}

function flushImportUpdates(tree: Tree): void {
  for (const [filePath, updates] of pendingImportUpdates.entries()) {
    updateMultipleImportSpecifiers(tree, filePath, updates);
  }
  pendingImportUpdates.clear();
}

• Queue import specifier updates per file and write them in a single pass.
• Introduce a multi-update helper to minimise repeated parsing.

Tasks

• Introduce a structure to queue import specifier updates grouped by file
• Implement a single-pass writer (e.g. updateMultipleImportSpecifiers) that applies all queued rewrites per file
• Ensure scheduling and flushing hooks integrate cleanly with existing caching layers

Definition of Done

• Existing benchmark and stress test suites are run before and after the change; include the numbers in the PR description. This is a mandatory gate.
• Unit/e2e tests remain green.
• Add documentation or comments covering the batching lifecycle.