Fix tree filter and URL canonicality for filter state

- Root entries in tree view filtered strictly by entry_matches_filter;
  a parent no longer appears just because a descendant matches
- Expanded children always shown unfiltered (tree navigation intent)
- build_url always writes ?status=<val> so URL is fully canonical;
  apply_search falls back to open for absent/empty param (old URLs)

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

public/app.mjs

@@ -307,8 +307,6 @@ function make_entry_row(entry, children_map) {
 }
 
 function render_tree_node(entry, children_map) {
-	if (!entry_matches_filter(entry)) { return null; }
-
 	const children = children_map.get(entry.id) ?? [];
 	const node = document.createElement('div');
 	node.className = 'task-node';
@@ -318,8 +316,7 @@ function render_tree_node(entry, children_map) {
 		const children_el = document.createElement('div');
 		children_el.className = 'task-children';
 		for (const child of children) {
-			const child_node = render_tree_node(child, children_map);
-			if (child_node) { children_el.appendChild(child_node); }
+			children_el.appendChild(render_tree_node(child, children_map));
 		}
 		node.appendChild(children_el);
 	}
@@ -649,11 +646,10 @@ function navigate_new(type, parent_id) {
 
 function build_url(hash) {
 	const params = new URLSearchParams();
-	if (state.filter_status !== 'open') { params.set('status', state.filter_status || 'all'); }
+	params.set('status', state.filter_status || 'all');
 	if (state.filter_priority) { params.set('priority', state.filter_priority); }
 	if (state.search)          { params.set('search', state.search); }
-	const qs = params.toString();
-	return (qs ? '?' + qs : '') + '#' + hash;
+	return '?' + params.toString() + '#' + hash;
 }
 
 function apply_search() {