feat : refactor to use autosave.ts for stygian

lib/editor/autosave.ts

@@ -48,6 +48,10 @@ export class AutosaveCoordinator<Draft, Payload, Snapshot = unknown> {
     return this.version;
   }
 
+  updateVersion(version: number): void {
+    this.version = Math.max(this.version, version);
+  }
+
   schedule(draft: Draft): void {
     if (this.disposed) return;
     this.pending = draft;
@@ -61,6 +65,14 @@ export class AutosaveCoordinator<Draft, Payload, Snapshot = unknown> {
     );
   }
 
+  cancelPending(): void {
+    this.pending = undefined;
+    this.generation += 1;
+    this.clearDebounce();
+    if (this.retryTimer !== undefined) this.saving = false;
+    this.clearRetry();
+  }
+
   async flush(): Promise<void> {
     this.clearDebounce();
     if (this.disposed || this.saving || this.pending === undefined) return;
@@ -101,11 +113,12 @@ export class AutosaveCoordinator<Draft, Payload, Snapshot = unknown> {
 
     if (this.disposed) return;
     if (response.status === "saved") {
-      this.version = response.version;
+      this.updateVersion(response.version);
       this.saving = false;
-      this.options.onSaved?.(response.snapshot, response.version);
-      this.emit({ state: "saved", version: response.version, savedAt: new Date() });
-      if (this.pending !== undefined) void this.flush();
+      if (Object.is(this.pending, draft)) this.cancelPending();
+      this.options.onSaved?.(response.snapshot, this.version);
+      this.emit({ state: "saved", version: this.version, savedAt: new Date() });
+      if (this.pending !== undefined && this.debounceTimer === undefined) void this.flush();
       return;
     }