Fix layout: checkbox-row full-width in grid, shared-input overflow fix

- checkbox-row now spans full grid width (grid-column: 1 / -1)
- Fixed shared link input: min-width:0, overflow:hidden, text-overflow:ellipsis
- Made '(sends the plan as-is)' a muted inline span instead of all-caps label text
- Removed unnecessary margin-bottom on checkbox-row

index.html

@@ -173,7 +173,8 @@
     border: 1px solid var(--border);
     border-radius: var(--radius-sm);
     padding: 10px 14px;
-    margin-bottom: 18px;
+    margin-bottom: 0;
+    grid-column: 1 / -1;
   }
   .tg-link {
     display: inline-flex;
@@ -378,6 +379,7 @@
   }
   .shared-link-row input {
     flex: 1;
+    min-width: 0;
     font-size: 0.78rem;
     font-family: monospace;
     color: var(--accent);
@@ -386,6 +388,9 @@
     border-radius: var(--radius-sm);
     padding: 7px 10px;
     outline: none;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
   }
   .copy-sm-btn {
     background: var(--accent);
@@ -517,7 +522,7 @@
   </div>
 
   <div class="control-group" style="grid-column: 1 / -1;">
-    <label>Share this link (sends the plan as-is)</label>
+    <label>Share this link <span style="font-weight:400;color:var(--text-muted);text-transform:none;letter-spacing:0;font-size:0.68rem;">(sends the plan as-is)</span></label>
     <div class="shared-link-row">
       <input type="text" id="sharedLink" readonly>
       <button class="copy-sm-btn" id="copyLinkBtn" onclick="copySharedLink()">📄 Copy</button>