fix(studio): document SELF_WRITE_SUPPRESS_MS heuristic; fix pre-existing TS errors

Reviewer noted the 2 s suppress window is a footgun. Add a comment explaining
the trade-off (short = echo fires anyway; long = masks real edits) and naming
the long-term fix (sequence number / content hash on the persist event).

Also fix three pre-existing issues in useDomEditCommits.ts on this branch:
- PatchOperation was used in UseDomEditCommitsParams but not imported
- onTrySdkPersist was called in persistDomEditOperations but missing from
  both the interface and the function's destructure pattern
- onTrySdkPersist missing from useCallback deps (react-hooks/exhaustive-deps)

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

Co-authored-by: Miguel Ángel <miguel07alm@protonmail.com>

Author: vanceingalls

packages/studio/src/hooks/useDomEditCommits.ts

@@ -9,6 +9,7 @@ import { buildDomEditPatchTarget, type DomEditSelection } from "../components/ed
 import { fontFamilyFromAssetPath, type ImportedFontAsset } from "../components/editor/fontAssets";
 import type { EditHistoryKind } from "../utils/editHistory";
 import type { PersistDomEditOperations } from "./domEditCommitTypes";
+import type { PatchOperation } from "../utils/sourcePatcher";
 import { useDomEditPositionPatchCommit } from "./useDomEditPositionPatchCommit";
 import { useDomEditTextCommits } from "./useDomEditTextCommits";
 import { useDomGeometryCommits } from "./useDomGeometryCommits";
@@ -77,6 +78,13 @@ export interface UseDomEditCommitsParams {
   ) => Promise<DomEditSelection | null>;
   /** Stage 7 Step 3b: called after a successful server-side element patch. */
   onDomEditPersisted?: (selection: DomEditSelection, operations: PatchOperation[]) => void;
+  /** Stage 7 Step 3c: called before the server-side patch path; returns true if SDK handled it. */
+  onTrySdkPersist?: (
+    selection: DomEditSelection,
+    operations: PatchOperation[],
+    originalContent: string,
+    targetPath: string,
+  ) => Promise<boolean>;
 }
 
 export function useDomEditCommits({
@@ -98,6 +106,7 @@ export function useDomEditCommits({
   refreshDomEditSelectionFromPreview,
   buildDomSelectionFromTarget,
   onDomEditPersisted,
+  onTrySdkPersist,
 }: UseDomEditCommitsParams) {
   const resolveImportedFontAsset = useCallback(
     (fontFamilyValue: string): ImportedFontAsset | null => {
@@ -237,6 +246,7 @@ export function useDomEditCommits({
       reloadPreview,
       showToast,
       onDomEditPersisted,
+      onTrySdkPersist,
     ],
   );
 

packages/studio/src/hooks/useSdkSession.ts

@@ -28,6 +28,12 @@ export function shouldReloadSdkSession(payload: unknown, activeCompPath: string
  * is therefore purely additive — no SDK self-write exists yet, so there is no
  * persist echo. Step 3c must add self-write suppression once dispatch writes.
  */
+// Time-window heuristic: suppress file-change reloads for 2 s after our own
+// SDK cutover write, to avoid an echo-reload on the write we just committed.
+// Footgun: if 2 s is too short (slow FS / network) the reload fires anyway;
+// if too long it masks a legitimate external edit. The long-term shape is a
+// sequence number or content hash threaded through the persist event so the
+// comparison is exact rather than time-based.
 const SELF_WRITE_SUPPRESS_MS = 2000;
 
 export function useSdkSession(