feat(import): remember the user's import selection

Yaak now remembers, per item of a linked import source, whether the user
wants it. A mapping row that still points at a model means wanted, so
re-imports merge into it; a row with no model behind it means not wanted,
so re-imports leave it alone. Wanted-ness is structural rather than a flag:
deleting the model locally, or turning the item down in the preview, is
what makes it not wanted.

- import_source_resources drops `snapshot` for a nullable `content_hash`
  and lets `model_id` be NULL. The migration keeps every beta row's
  key to model mapping and starts hashes empty; until a hash is recorded,
  a difference can't be attributed to either side, so the item is offered
  once as a conflict that keeps local changes.
- comparable() ignores sortPriority. Importers number it from source
  order, so inserting one operation used to plan a fake update for
  everything after it. The trade is that pure reorders don't propagate.
- Keys the user turned down come back as unchecked "not imported" rows
  instead of being re-offered as new resources or resurrected. Checking
  one imports it under the same source key and pulls in the folders it
  needs.
- An imported resource the source moves into a folder that isn't imported
  is offered as a deletion, with a tooltip pointing at the folder.
- Plan-time source resolution binds by source-key overlap instead of by
  path, so a renamed or moved file merges into what it created and heals
  the stored origin. Several sources sharing keys never guess-merge: the
  plan says so and imports everything as new.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/yaak-client/components/ImportDataDialog.tsx

@@ -261,13 +261,20 @@ function LoadedImportDataDialog({
   const itemTree = useMemo(() => buildItemTree(items), [items]);
 
   // A folder row's checkbox aggregates its subtree the way the git commit tree does: creates and
-  // updates toggle together, while removals only ever cascade beneath a removed folder.
+  // updates toggle together, while removals only ever cascade beneath a removed folder. Checking
+  // anything also brings back the folders it needs to live in.
   const toggleNode = (node: CheckboxTreeNode<ImportPlanItem>, checked: boolean) => {
     const targets = new Set(
       collectItems(node)
         .filter((i) => togglesWith(node.data, i))
         .map((i) => i.modelId),
     );
+    if (checked) {
+      const byId = new Map(items.map((i) => [i.modelId, i]));
+      for (const ancestor of ancestorsOf(node.data, byId)) {
+        if (ancestor.action === "not_imported") targets.add(ancestor.modelId);
+      }
+    }
     setItems((prev) => prev.map((i) => (targets.has(i.modelId) ? { ...i, selected: checked } : i)));
   };
 
@@ -283,19 +290,17 @@ function LoadedImportDataDialog({
     const disabled = new Set<string>();
     const byId = new Map(items.map((i) => [i.modelId, i]));
     for (const item of items) {
-      const seen = new Set<string>();
-      let parentId = item.parentId;
-      while (parentId != null && !seen.has(parentId)) {
-        seen.add(parentId);
-        const parent = byId.get(parentId);
-        if (parent == null || parent.model !== "folder") break;
-        if (parent.action === "create" && !parent.selected && item.action !== "delete") {
+      for (const parent of ancestorsOf(item, byId)) {
+        if (parent.model !== "folder") break;
+        const missing =
+          (parent.action === "create" || parent.action === "not_imported") && !parent.selected;
+        // A not-imported row stays checkable: checking it brings its folders back with it
+        if (missing && item.action !== "delete" && item.action !== "not_imported") {
           disabled.add(item.modelId);
         }
         if (parent.action === "delete" && parent.selected && item.action === "delete") {
           disabled.add(item.modelId);
         }
-        parentId = parent.parentId;
       }
     }
     return disabled;
@@ -358,6 +363,7 @@ function LoadedImportDataDialog({
             checked={nodeCheckedStatus}
             onCheck={toggleNode}
             isCheckboxDisabled={(n) => disabledIds.has(n.key)}
+            isCollapsedByDefault={(n) => n.data.action === "not_imported"}
             isRelevant={(n) => n.data.model === "workspace" || n.data.action !== "unchanged"}
             renderRow={(n) => <ImportTreeRow item={n.data} onResolveConflict={resolveConflict} />}
           />
@@ -589,6 +595,7 @@ function ImportTreeRow({
               item.action === "update" && "text-info",
               item.action === "delete" && "text-danger",
               item.action === "keep_local" && item.selected && "text-warning",
+              item.action === "not_imported" && "text-text-subtlest",
             )}
           >
             {actionLabel(item)}
@@ -610,6 +617,8 @@ function actionLabel(item: ImportPlanItem): string | null {
       return "removed";
     case "keep_local":
       return "edited";
+    case "not_imported":
+      return "not imported";
     default:
       return null;
   }
@@ -622,16 +631,35 @@ function actionHelp(item: ImportPlanItem): string | null {
     case "update":
       return "Changed since the last import";
     case "delete":
-      return "Deleted since the last import";
+      return item.reason === "moved_into_not_imported_folder"
+        ? "Moved into a folder that isn't imported. Import that folder instead to follow the move"
+        : "Deleted since the last import";
     case "keep_local":
       return "Local edits made since the last import. Importing will revert them if checked";
     case "conflict":
       return "Changed both here and in the file since the last import";
+    case "not_imported":
+      return "In the file, but not imported. Check it to import it";
     default:
       return null;
   }
 }
 
+/** Every plan item above `item`, nearest first. */
+function ancestorsOf(item: ImportPlanItem, byId: Map<string, ImportPlanItem>): ImportPlanItem[] {
+  const ancestors: ImportPlanItem[] = [];
+  const seen = new Set<string>();
+  let parentId = item.parentId;
+  while (parentId != null && !seen.has(parentId)) {
+    seen.add(parentId);
+    const parent = byId.get(parentId);
+    if (parent == null) break;
+    ancestors.push(parent);
+    parentId = parent.parentId;
+  }
+  return ancestors;
+}
+
 function buildItemTree(items: ImportPlanItem[]): CheckboxTreeNode<ImportPlanItem>[] {
   const byId = new Map(items.map((i) => [i.modelId, i]));
   const childrenOf = new Map<string, ImportPlanItem[]>();
@@ -678,7 +706,7 @@ function togglesWith(root: ImportPlanItem, item: ImportPlanItem): boolean {
   if (item.action === "keep_local") {
     return root.modelId === item.modelId && item.model !== "folder";
   }
-  return item.action === "create" || item.action === "update";
+  return item.action === "create" || item.action === "update" || item.action === "not_imported";
 }
 
 function nodeCheckedStatus(

apps/yaak-client/components/core/CheckboxTree.tsx

@@ -21,6 +21,8 @@ interface Props<T> {
   isCheckboxDisabled?: (node: CheckboxTreeNode<T>) => boolean;
   /** An irrelevant row is hidden unless one of its descendants is relevant */
   isRelevant: (node: CheckboxTreeNode<T>) => boolean;
+  /** A node that starts collapsed, so a large subtree doesn't crowd out the rest */
+  isCollapsedByDefault?: (node: CheckboxTreeNode<T>) => boolean;
   renderRow: (node: CheckboxTreeNode<T>) => ReactNode;
   onSelectRow?: (node: CheckboxTreeNode<T>) => void;
   canSelectRow?: (node: CheckboxTreeNode<T>) => boolean;
@@ -29,7 +31,9 @@ interface Props<T> {
 
 export function CheckboxTree<T>(props: Props<T>) {
   const { node, depth = 0 } = props;
-  const [collapsed, setCollapsed] = useState<boolean>(false);
+  const [collapsed, setCollapsed] = useState<boolean>(
+    () => props.isCollapsedByDefault?.(node) ?? false,
+  );
   if (!hasRelevantNode(node, props.isRelevant)) return null;
 
   const checked = props.checked(node);