feat(f9): AttributionController.spansFor — authorship spans for the preview

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/attributionController.ts

@@ -18,6 +18,7 @@ import { applyChange, coalesce, type LiveSpan } from "./attributionTracker";
 import { minimizeReplace, PendingEditRegistry } from "./pendingEdits";
 import type { VersionGuard } from "./versionGuard";
 import { isAuthorable } from "./workspacePath";
+import type { AuthorSpan } from "./trackChangesModel";
 
 /** Test-facing snapshot of live attribution state for a document. */
 export interface RenderedSpan {
@@ -400,6 +401,19 @@ export class AttributionController implements vscode.Disposable {
   getOrphanCount(docPath: string): number {
     return this.docs.get(docPath)?.orphans.length ?? 0;
   }
+
+  /**
+   * F9: the document's live attribution as authorship spans for the preview —
+   * current-buffer char ranges mapped to author kind (agent→claude). Computes
+   * the document key internally, so callers pass a TextDocument, not the key.
+   */
+  spansFor(document: vscode.TextDocument): AuthorSpan[] {
+    return this.getSpans(this.keyOf(document)).map((s) => ({
+      start: s.range.start,
+      end: s.range.end,
+      author: s.authorKind === "agent" ? "claude" : "human",
+    }));
+  }
   isVisible(): boolean {
     return this.visible;
   }