fix(contracts): widen the block-library list column

Block names ellipsized to ~4-6 characters ("Vertr...", "Bildr..."). The
tooltip added earlier made them recoverable but the list still was not
scannable.

The file's "intentionally mirrors EmailConfigPage's Templates tab" comment was
the reason the ratio was left alone. Re-evaluated: both pages render in the
same Settings shell so the ratio is shared, but the content is not. A block
tile spends a fixed ~105px of its row on the "System" badge plus the n/6 pill,
and block names are long German noun phrases; EmailConfigPage's tiles carry
one badge and short display names ("Gallery Created"). So the shared ratio is
not simply wrong -- it is wrong here. Diverged only here: lg:grid-cols-3 /
col-span-2 becomes lg:grid-cols-5 with a 2/3 split (40/60). Mobile stack
untouched, and the comment now names the divergence and why.

Refs testplan REPORT.md A5.

frontend/src/pages/admin/contracts/BlockLibraryPage.tsx

@@ -2,7 +2,9 @@
  * Admin → Contract block library.
  *
  * Two-column layout intentionally mirroring EmailConfigPage's Templates
- * tab so admins navigate one shape across all template-style editors:
+ * tab so admins navigate one shape across all template-style editors
+ * (the one deliberate divergence is the column ratio — see the grid
+ * below):
  *   - Left: sticky sidebar with sections (basics / scope / privacy /
  *     commercial / nda / closing) as uppercase headings, blocks listed
  *     below each, "+ New block" button at the top. Selected block
@@ -267,11 +269,19 @@ export const BlockLibraryPage: React.FC = () => {
       </div>
 
       {isLoading ? <Loading /> : (
-        <div className="grid grid-cols-1 lg:grid-cols-3 gap-6">
+        // 2/5 + 3/5, not the email tab's 1/3 + 2/3. Same shape, wider
+        // list column — deliberate (QA S13): a block tile spends a fixed
+        // ~105px of its row on the "System" badge plus the n/6 pill, and
+        // block names are long noun phrases ("Vertragsgegenstand und
+        // Leistungsumfang"). At 1/3 inside the Settings shell that left
+        // the name a handful of characters ("Vertr…"). The email tab's
+        // display names are short and it carries only one badge, so its
+        // ratio stays as-is rather than both moving together.
+        <div className="grid grid-cols-1 lg:grid-cols-5 gap-6">
           {/* Sidebar — same shape as EmailConfigPage templates sidebar:
               Card padding="sm" + h3 + +New button up top, then a
               section-grouped list of block tiles. */}
-          <Card padding="sm">
+          <Card padding="sm" className="lg:col-span-2">
             <div className="flex items-center justify-between mb-4">
               <h3 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100">
                 {t('contracts.blocks.sidebarHeading', 'Blocks')}
@@ -359,9 +369,8 @@ export const BlockLibraryPage: React.FC = () => {
             </div>
           </Card>
 
-          {/* Right panel — edit / create form. lg:col-span-2 matches the
-              email-templates layout exactly. */}
-          <div className="lg:col-span-2">
+          {/* Right panel — edit / create form. */}
+          <div className="lg:col-span-3">
             {selection === null ? (
               <Card padding="md">
                 <p className="text-center text-neutral-500 dark:text-neutral-400 py-8">