Derive selection stores and subscribe to lastAdded

Convert computed getters for selected paths and list selection into
derived stores and replace the derived-lastAdded setup with a direct
subscription. This aligns selection state with reactive stores, avoids
creating intermediate derived getters, and ensures focus sync uses the
latest lastAdded value via subscribe so focus updates happen reliably
when active.
Return true from key handlers and guard onclick onselect

Fix navigation and selection handling by making keyboard handlers return
true when they successfully handle an event, and by guarding onclick
onselect so it only fires when the clicked item is selected. Previously
keyboard activation and extra handlers returned nothing which prevented
higher-level logic from stopping further processing; navigation also
didn't short-circuit so focus could move to the wrong index. The onclick
change prevents emitting an onselect callback for a click that doesn't
actually result in selection.
Only claim navigation events when index changes

Prevent the FileListItems component from swallowing arrow/vim navigation
events if the navigation result doesn't move focus. Previously, reaching
the end of the list would still be treated as handled and would not fall
through to the focus manager, preventing users from moving to the next
commit. This change makes the component only claim the event when the
navigated index actually differs from the current index, restoring the
expected fall-through behavior.

Author: mtsgrd

apps/desktop/src/components/FileListItems.svelte

@@ -127,27 +127,32 @@
 				// 1. Activation keys (Enter/Space/l)
 				if (controller.handleActivation(change, idx, e)) {
 					onselect?.(change, idx);
-					return;
+					return true;
 				}
 				// 2. Extra handlers (e.g. AI shortcuts)
 				if (extraKeyHandlers) {
 					for (const handler of extraKeyHandlers) {
-						if (handler(change, idx, e)) return;
+						if (handler(change, idx, e)) return true;
 					}
 				}
-				// 3. Arrow/vim navigation
+				// 3. Arrow/vim navigation — only claim the event if we moved
 				const navigatedIndex = controller.handleNavigation(e);
-				if (navigatedIndex !== undefined) {
+				if (navigatedIndex !== undefined && navigatedIndex !== idx) {
 					const navigatedChange = controller.changes[navigatedIndex];
-					if (navigatedChange) onselect?.(navigatedChange, navigatedIndex);
+					if (navigatedChange) {
+						onselect?.(navigatedChange, navigatedIndex);
+					}
+					return true;
 				}
 			},
 			focusable: true,
 		}}
 		onclick={(e) => {
 			e.stopPropagation();
 			controller.select(e, change, idx);
-			onselect?.(change, idx);
+			if (controller.isSelected(change.path)) {
+				onselect?.(change, idx);
+			}
 		}}
 		{conflictEntries}
 	/>

apps/desktop/src/lib/selection/fileListController.svelte.ts

@@ -58,6 +58,10 @@ export class FileListController {
 	private getAllowUnselect: () => boolean;
 
 	active = $state(false);
+	readonly selectedPaths = $derived(new Set(this.selectedFileIds.map((f) => f.path)));
+	readonly hasSelectionInList = $derived(
+		this.changes.some((change) => this.selectedPaths.has(change.path)),
+	);
 
 	constructor(params: {
 		changes: () => TreeChange[];
@@ -70,18 +74,17 @@ export class FileListController {
 		this.getSelectionId = params.selectionId;
 		this.getAllowUnselect = params.allowUnselect ?? (() => true);
 
-		const currentSelection = $derived(this.idSelection.getById(this.getSelectionId()));
-		const lastAdded = $derived(currentSelection.lastAdded);
-		const lastAddedIndex = $derived(get(lastAdded)?.index);
-
 		$effect(() => {
-			if (lastAddedIndex !== undefined) {
-				untrack(() => {
-					if (this.active) {
-						this.focusManager.focusNthSibling(lastAddedIndex);
-					}
-				});
-			}
+			const store = this.idSelection.getById(this.getSelectionId()).lastAdded;
+			return store.subscribe((value) => {
+				if (value?.index !== undefined) {
+					untrack(() => {
+						if (this.active) {
+							this.focusManager.focusNthSibling(value.index);
+						}
+					});
+				}
+			});
 		});
 	}
 
@@ -101,14 +104,6 @@ export class FileListController {
 		return this.idSelection.values(this.selectionId);
 	}
 
-	get selectedPaths(): Set<string> {
-		return new Set(this.selectedFileIds.map((f) => f.path));
-	}
-
-	get hasSelectionInList(): boolean {
-		return this.changes.some((change) => this.selectedPaths.has(change.path));
-	}
-
 	isSelected(path: string): boolean {
 		return this.idSelection.has(path, this.selectionId);
 	}