feat(webview): Accept/Reject + dropdown, rejectAll, control parity (#64, INV-53)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/trackChangesPreview.ts

@@ -44,7 +44,8 @@ type ToolbarMsg =
   | { type: "pinBaseline" }
   | { type: "askClaude"; scope: "document" }
   | { type: "askClaude"; scope: "selection"; start: number; end: number }
-  | { type: "acceptAll" };
+  | { type: "acceptAll" }
+  | { type: "rejectAll" };
 
 export class TrackChangesPreviewController implements vscode.Disposable {
   private readonly disposables: vscode.Disposable[] = [];
@@ -190,8 +191,7 @@ export class TrackChangesPreviewController implements vscode.Disposable {
         .acceptById(this.proposals.keyFor(document), m.proposalId)
         .then(() => this.refresh(document));
     } else if (m?.type === "reject" && m.proposalId) {
-      this.proposals.rejectById(this.proposals.keyFor(document), m.proposalId);
-      this.refresh(document);
+      void this.proposals.rejectByIdInPlace(this.proposals.keyFor(document), m.proposalId).then(() => this.refresh(document));
     } else if (m?.type === "pinBaseline") {
       // F6 baseline store re-render arrives via the onDidChangeBaseline subscription.
       this.diffView.pin(document);
@@ -202,6 +202,8 @@ export class TrackChangesPreviewController implements vscode.Disposable {
     } else if (m?.type === "acceptAll") {
       // #46 (INV-42): batch-accept every pending proposal on this doc, then report.
       void this.acceptAll(document);
+    } else if (m?.type === "rejectAll") {
+      void this.rejectAll(document);
     }
   }
 
@@ -222,6 +224,17 @@ export class TrackChangesPreviewController implements vscode.Disposable {
     );
   }
 
+  /** #64 (INV-53): revert every pending proposal on the document; report the count. */
+  async rejectAll(document: vscode.TextDocument): Promise<void> {
+    const { reverted } = await this.proposals.rejectAll(document);
+    this.refresh(document);
+    if (reverted > 0) {
+      void vscode.window.showInformationMessage(
+        `Cowriting: rejected ${reverted} proposal${reverted === 1 ? "" : "s"}.`,
+      );
+    }
+  }
+
   /**
    * Where the inline Ask-Claude input anchors: a range edit pins to its selection;
    * a whole-document edit pins to the editor's cursor line if this document is the