fix(ui): the filter pills open their menu on screen again

The pill trigger paints its own label spans and mounts no SelectValue,
and Radix's item-aligned placement silently skips all positioning when
the value node is absent — the open menu laid out below the
height-locked app shell, fully off-viewport, which reads as a dead
control. The mood and type/source pills on the mood and measurements
lists were affected since the unified filter rail landed in v1.16.1.
Popper placement has no value-node dependency and anchors the menu
under the pill like the date-range popover next to it.

src/components/ui/__tests__/filter-bar.test.tsx

@@ -1,4 +1,6 @@
 import { describe, expect, it } from "vitest";
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
 import { renderToStaticMarkup } from "react-dom/server";
 
 import { I18nProvider } from "@/lib/i18n/context";
@@ -141,3 +143,21 @@ describe("FilterBar shell", () => {
     expect(html).toContain('aria-label="Filter entfernen: Quelle"');
   });
 });
+
+describe("FilterBarSelect — menu positioning (source pin)", () => {
+  // The pill trigger paints its own label spans and mounts no
+  // `<SelectValue>`. Radix's default item-aligned placement silently
+  // skips ALL positioning when the value node is absent — the open
+  // menu then lays out below the height-locked app shell, fully
+  // off-viewport, which users report as "clicking does nothing". SSR
+  // markup cannot exercise an open portal, so this pins the source:
+  // the content must request popper placement, which has no
+  // value-node dependency.
+  it("requests popper placement on the select content", () => {
+    const src = readFileSync(
+      join(process.cwd(), "src/components/ui/filter-bar.tsx"),
+      "utf8",
+    );
+    expect(src).toMatch(/<SelectContent\s+position="popper"\s+align="start">/);
+  });
+});

src/components/ui/filter-bar.tsx

@@ -175,7 +175,14 @@ export function FilterBarSelect({
             <span className="text-muted-foreground">{label}</span>
           )}
         </SelectTrigger>
-        <SelectContent>
+        {/* `position="popper"` is load-bearing: this trigger paints its
+            own label spans and mounts no `SelectValue`, and Radix's
+            default item-aligned placement silently skips ALL positioning
+            when the value node is absent — the open menu then lays out
+            below the height-locked app shell, fully off-viewport. Popper
+            placement has no value-node dependency and anchors the menu
+            under the pill like the date-range popover next to it. */}
+        <SelectContent position="popper" align="start">
           <SelectItem value={allValue}>{allLabel}</SelectItem>
           {options.map((opt) => (
             <SelectItem key={opt.value} value={opt.value}>