fix(ui): unify list filters across all pages (bare controls, standard sizes)

Every list-page FilterBar now follows one spec: bare controls (no Field label rows — which broke flex-end alignment), standardized widths (search 1 1 320px grows; small selects 0 0 160px; entity selects 0 0 220px; MonthField 0 0 180px; dates 0 0 150px), consistent 'Všechny/Všichni/Všechna <entity>' defaults, and a placeholder on every search. TripsAdmin's separate month-Select + year-Select collapse into one MonthField (yyyy-MM, split at the query boundary) — matching Attendance/TripsHistory. The 4 labeled attendance/trips pages move off the Field wrapper; Projects & ReceivedInvoices move their inline search into a FilterBar. Chrome-verified all ~18 filter pages in light + the existing theme.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/admin/pages/Projects.tsx

@@ -25,6 +25,7 @@ import {
   Modal,
   ConfirmDialog,
   Field,
+  FilterBar,
   TextField,
   Select,
   DateField,
@@ -365,17 +366,19 @@ export default function Projects() {
         )}
       </Box>
 
-      <Box sx={{ mb: 3 }}>
-        <TextField
-          value={search}
-          onChange={(e) => {
-            setSearch(e.target.value);
-            setPage(1);
-          }}
-          placeholder="Hledat podle čísla, názvu nebo zákazníka..."
-          fullWidth
-        />
-      </Box>
+      <FilterBar>
+        <Box sx={{ flex: "1 1 320px" }}>
+          <TextField
+            value={search}
+            onChange={(e) => {
+              setSearch(e.target.value);
+              setPage(1);
+            }}
+            placeholder="Hledat podle čísla, názvu nebo zákazníka..."
+            fullWidth
+          />
+        </Box>
+      </FilterBar>
 
       <Card sx={{ opacity: isFetching ? 0.6 : 1, transition: "opacity .2s" }}>
         <DataTable<Project>