fix: invoice PDF — tighter layout, more room for items

- Page margins reduced, content width 186mm
- Header/grid padding tightened
- Table headers 8.5pt normal case, cells 4px padding
- Footer flows naturally across pages (no forced page break)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/routes/admin/invoices-pdf.ts

@@ -495,14 +495,14 @@ export default async function invoicesPdfRoutes(
 <style>
   @page {
     size: A4;
-    margin: 12mm 15mm 15mm 15mm;
+    margin: 8mm 12mm 10mm 12mm;
   }
   * { margin: 0; padding: 0; box-sizing: border-box; }
   html, body {
     font-family: "Segoe UI", Tahoma, Arial, sans-serif;
     font-size: 10pt;
     color: #1a1a1a;
-    width: 180mm;
+    width: 186mm;
   }
 
   .invoice-page {
@@ -513,8 +513,6 @@ export default async function invoicesPdfRoutes(
   .invoice-content { flex: 1 1 auto; }
   .invoice-footer {
     flex-shrink: 0;
-    page-break-inside: avoid;
-    break-inside: avoid;
   }
 
   .accent { color: #de3a3a; }
@@ -524,8 +522,8 @@ export default async function invoicesPdfRoutes(
     display: flex;
     justify-content: space-between;
     align-items: center;
-    margin-bottom: 3mm;
-    padding-bottom: 3mm;
+    margin-bottom: 1mm;
+    padding-bottom: 1mm;
     border-bottom: 2pt solid #de3a3a;
   }
   .invoice-header .left {
@@ -557,10 +555,10 @@ export default async function invoicesPdfRoutes(
     border: 0.5pt solid #d0d0d0;
     border-collapse: collapse;
     width: 100%;
-    margin-bottom: 3mm;
+    margin-bottom: 1mm;
   }
   .header-grid td {
-    padding: 3mm 4mm;
+    padding: 2mm 3mm;
     border: 0.5pt solid #d0d0d0;
     vertical-align: top;
     width: 50%;
@@ -643,20 +641,18 @@ export default async function invoicesPdfRoutes(
     margin-bottom: 2mm;
   }
   table.items thead th {
-    font-size: 9pt;
+    font-size: 8.5pt;
     font-weight: 600;
     color: #646464;
-    padding: 6px 8px;
+    padding: 4px 4px;
     text-align: left;
-    letter-spacing: 0.02em;
-    text-transform: uppercase;
     border-bottom: 0.5pt solid #d0d0d0;
     white-space: nowrap;
   }
   table.items thead th.center { text-align: center; }
   table.items thead th.right { text-align: right; }
   table.items tbody td {
-    padding: 5px 8px;
+    padding: 4px 4px;
     border-bottom: 0.5pt solid #e0e0e0;
     vertical-align: middle;
     color: #1a1a1a;