Clarify active grid filters

docs/spec/07-implementation-phases-todo.md

@@ -287,6 +287,8 @@ Implemented layout foundation:
 - the toolbar remains reachable while the page scrolls
 - programmatic grid focus preserves the viewport during undo/redo reloads
 - wide tables no longer expand the surrounding browser layout
+- active sorts and filters are summarized above the grid and can be removed individually or reset together
+- column filter buttons show their selected-value count and filter menus explain their matching behavior
 
 Acceptance criteria:
 

src/app/globals.css

@@ -71,6 +71,44 @@ body {
   opacity: 0.45;
 }
 
+.active-view-summary {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 0.35rem;
+  padding: 0.4rem 0.5rem;
+  border: 1px solid #bfdbfe;
+  border-radius: 5px;
+  background: #eff6ff;
+  color: #1e3a5f;
+  font-size: 0.78rem;
+}
+
+.active-view-label {
+  font-weight: 600;
+}
+
+.active-view-chip,
+.active-view-reset {
+  border: 1px solid #93b4df;
+  border-radius: 999px;
+  background: #fff;
+  color: #1e3a5f;
+  padding: 0.18rem 0.48rem;
+  font-size: 0.76rem;
+  cursor: pointer;
+}
+
+.active-view-chip:hover,
+.active-view-reset:hover {
+  border-color: #2563eb;
+}
+
+.active-view-reset {
+  margin-left: auto;
+  font-weight: 600;
+}
+
 .column-settings-menu {
   position: absolute;
   z-index: 9;
@@ -278,6 +316,7 @@ body {
 .tree-grid .header-filter-btn.active {
   border-color: #2563eb;
   color: #2563eb;
+  background: #eff6ff;
 }
 
 .tree-grid .header-filter-menu {
@@ -293,13 +332,33 @@ body {
   padding: 0.35rem;
 }
 
+.tree-grid .header-filter-actions {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 0.4rem;
+  margin-bottom: 0.35rem;
+  font-size: 0.72rem;
+}
+
+.tree-grid .header-filter-explanation {
+  margin-bottom: 0.4rem;
+  color: #4b5563;
+  font-size: 0.72rem;
+  line-height: 1.3;
+  white-space: normal;
+}
+
 .tree-grid .header-filter-clear {
   border: 1px solid #c4cddc;
   background: #fff;
   border-radius: 3px;
   font-size: 0.72rem;
   padding: 0.12rem 0.3rem;
-  margin-bottom: 0.25rem;
+}
+
+.tree-grid .header-filter-clear:disabled {
+  opacity: 0.45;
 }
 
 .tree-grid .header-filter-values {

src/frontend/components/circuit-tree-editor.tsx

@@ -315,6 +315,15 @@ export function CircuitTreeEditor(props: { projectId: string; circuitListId: str
     [columnFilters]
   );
 
+  const activeColumnFilters = useMemo(
+    () =>
+      visibleColumns.flatMap((column) => {
+        const values = columnFilters[column.key] ?? [];
+        return values.length > 0 ? [{ column, values }] : [];
+      }),
+    [columnFilters, visibleColumns]
+  );
+
   const distinctValuesByColumn = useMemo(() => {
     // Filter options are generated only for visible columns to match current header UI.
     // Hidden columns still exist in row model, but are intentionally not filterable from header.
@@ -333,6 +342,67 @@ export function CircuitTreeEditor(props: { projectId: string; circuitListId: str
     return buildVisibleGridRows(filteredSortedSections);
   }, [filteredSortedSections]);
 
+  function clearColumnFilter(key: CellKey) {
+    setColumnFilters((current) => {
+      const next = { ...current };
+      delete next[key];
+      return next;
+    });
+    setOpenFilterColumn((current) => (current === key ? null : current));
+  }
+
+  function clearSortAndFilters() {
+    setSortState(null);
+    setColumnFilters({});
+    setOpenFilterColumn(null);
+  }
+
+  function renderActiveViewSummary() {
+    if (!sortState && activeColumnFilters.length === 0) {
+      return null;
+    }
+
+    const sortedColumn = sortState
+      ? allColumns.find((column) => column.key === sortState.key)
+      : undefined;
+
+    return (
+      <div className="active-view-summary" aria-label="Active sort and filters">
+        <span className="active-view-label">Active view</span>
+        {sortState ? (
+          <button
+            type="button"
+            className="active-view-chip"
+            onClick={() => setSortState(null)}
+            title="Remove sorting"
+          >
+            Sort: {sortedColumn?.label ?? sortState.key} ({sortState.direction === "asc" ? "ascending" : "descending"})
+            <span aria-hidden="true"> ×</span>
+          </button>
+        ) : null}
+        {activeColumnFilters.map(({ column, values }) => {
+          const shownValues = values.slice(0, 2).join(", ");
+          const valueSummary = values.length > 2 ? `${shownValues} +${values.length - 2}` : shownValues;
+          return (
+            <button
+              key={`active-filter-${column.key}`}
+              type="button"
+              className="active-view-chip"
+              onClick={() => clearColumnFilter(column.key)}
+              title={`Remove filter for ${column.label}`}
+            >
+              {column.label}: {valueSummary}
+              <span aria-hidden="true"> ×</span>
+            </button>
+          );
+        })}
+        <button type="button" className="active-view-reset" onClick={clearSortAndFilters}>
+          Reset view
+        </button>
+      </div>
+    );
+  }
+
   const searchableProjectDevices = useMemo(() => {
     const term = projectDeviceSearch.trim().toLowerCase();
     if (!term) {
@@ -2247,11 +2317,7 @@ export function CircuitTreeEditor(props: { projectId: string; circuitListId: str
           </button>
         <button
           type="button"
-          onClick={() => {
+          onClick={clearSortAndFilters}
-            setSortState(null);
-            setColumnFilters({});
-            setOpenFilterColumn(null);
-          }}
           disabled={!Boolean(sortState) && !hasActiveFilters}
         >
           Clear sort/filter
@@ -2303,6 +2369,7 @@ export function CircuitTreeEditor(props: { projectId: string; circuitListId: str
           </div>
         ) : null}
       </div>
+        {renderActiveViewSummary()}
         {error ? (
           <div className="notice error editor-error-notice" role="alert">
             <span>{error}</span>
@@ -2372,11 +2439,7 @@ export function CircuitTreeEditor(props: { projectId: string; circuitListId: str
         </button>
         <button
           type="button"
-          onClick={() => {
+          onClick={clearSortAndFilters}
-            setSortState(null);
-            setColumnFilters({});
-            setOpenFilterColumn(null);
-          }}
           disabled={!isSortedView && !hasActiveFilters}
         >
           Clear sort/filter
@@ -2425,6 +2488,7 @@ export function CircuitTreeEditor(props: { projectId: string; circuitListId: str
           </div>
         ) : null}
       </div>
+      {renderActiveViewSummary()}
       {hasActiveSortOrFilter ? (
         <div className="notice muted">Sorting/filtering is view-only. Renumber is disabled while sort/filter is active.</div>
       ) : null}
@@ -2587,24 +2651,36 @@ export function CircuitTreeEditor(props: { projectId: string; circuitListId: str
                       type="button"
                       className={`header-filter-btn ${(columnFilters[column.key]?.length ?? 0) > 0 ? "active" : ""}`}
                       onClick={() => setOpenFilterColumn((current) => (current === column.key ? null : column.key))}
+                      aria-pressed={(columnFilters[column.key]?.length ?? 0) > 0}
+                      title={
+                        (columnFilters[column.key]?.length ?? 0) > 0
+                          ? `${columnFilters[column.key]?.length} filter value(s) selected`
+                          : `Filter ${column.label}`
+                      }
                     >
-                      Filter
+                      Filter{(columnFilters[column.key]?.length ?? 0) > 0 ? ` (${columnFilters[column.key]?.length})` : ""}
                     </button>
                   </div>
                   {openFilterColumn === column.key ? (
                     <div className="header-filter-menu">
+                      <div className="header-filter-explanation">
+                        Select one or more values. A circuit is shown when its block contains any selected value.
+                      </div>
+                      <div className="header-filter-actions">
+                        <span>
+                          {(columnFilters[column.key]?.length ?? 0) > 0
+                            ? `${columnFilters[column.key]?.length} selected`
+                            : "Showing all"}
+                        </span>
                         <button
                           type="button"
                           className="header-filter-clear"
-                        onClick={() =>
+                          onClick={() => clearColumnFilter(column.key)}
-                          setColumnFilters((current) => ({
+                          disabled={(columnFilters[column.key]?.length ?? 0) === 0}
-                            ...current,
-                            [column.key]: [],
-                          }))
-                        }
                         >
-                        Clear
+                          Show all
                         </button>
+                      </div>
                       <div className="header-filter-values">
                         {distinctValuesByColumn[column.key].map((value) => {
                           const selected = columnFilters[column.key] ?? [];