compact filter list: one row per rule, smaller global type scale

Pico scales the root font up to 125% on wide screens, which made the
whole admin UI oversized. Pin it to 93.75% and tighten spacing tokens.

The filter list is now a dense table-like list: switch, priority, name,
condition chips, target folder, match stats and icon buttons on a single
row (~35 rules fit on one screen instead of ~4). Warnings collapse into
a ⚠ icon with tooltip; attachment and date conditions render as short
chips; the full condition list is in the row tooltip; double-click opens
the rule. Account picker, summary and main actions share one header row.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/static/style.css

@@ -3,8 +3,23 @@
 :root {
     --app-bg: #f6f7f9;
     --app-border: #e3e6ea;
+    /* Pico skaliert die Schrift auf breiten Bildschirmen bis 125% hoch —
+       für eine Verwaltungsoberfläche viel zu groß. Fest und kompakter. */
+    --pico-font-size: 93.75%;
+    --pico-line-height: 1.45;
+    --pico-spacing: 0.9rem;
+    --pico-form-element-spacing-vertical: 0.45rem;
+    --pico-form-element-spacing-horizontal: 0.7rem;
+    --pico-typography-spacing-vertical: 0.8rem;
+    --pico-block-spacing-vertical: 1rem;
+    --pico-block-spacing-horizontal: 1rem;
 }
 
+h1 { font-size: 1.6rem; }
+h2 { font-size: 1.3rem; }
+h3 { font-size: 1.1rem; }
+h4 { font-size: 1rem; }
+
 body {
     background: var(--app-bg);
 }
@@ -12,9 +27,14 @@ body {
 nav.container-fluid {
     background: #fff;
     border-bottom: 1px solid var(--app-border);
-    padding-top: 0.25rem;
-    padding-bottom: 0.25rem;
-    margin-bottom: 1.5rem;
+    padding-top: 0;
+    padding-bottom: 0;
+    margin-bottom: 1rem;
+}
+
+nav li {
+    padding-top: 0.6rem;
+    padding-bottom: 0.6rem;
 }
 
 nav .brand {