fix(emcn): match Folder icon geometry to FolderOpen (#6262)

Folder and FolderOpen toggle in place in the sidebar folder rows, but
carried incompatible geometry: Folder was a fill-based outline in a
tight 14.5x13 box at stroke 0.3, while FolderOpen is the house-standard
stroke outline in -1 -2 24 24 at stroke 1.55.

A square size-[16px] therefore scaled the closed folder to ~16x14.3px
where the open one renders ~11.3x10px, so expanding a folder visibly
shrank its icon.

Redraw Folder as FolderOpen's own body outline closed along the
bottom-right, so the pair shares a silhouette, a box and a stroke
weight by construction.

packages/emcn/src/icons/folder.tsx

@@ -1,26 +1,31 @@
 import type { SVGProps } from 'react'
 
 /**
- * Folder icon component
+ * Folder icon component - closed counterpart of {@link FolderOpen}
+ *
+ * The path is FolderOpen's own body outline, closed along the bottom-right, so
+ * the pair shares a silhouette, a box and a stroke weight. The two toggle in
+ * place (sidebar folder rows), which makes any divergence read as the icon
+ * changing size on expand.
+ *
  * @param props - SVG properties including className, fill, etc.
  */
 export function Folder(props: SVGProps<SVGSVGElement>) {
   return (
     <svg
-      width='14.5'
-      height='13'
-      viewBox='0 0 14.5 13'
+      width='24'
+      height='24'
+      viewBox='-1 -2 24 24'
       fill='none'
+      stroke='currentColor'
+      strokeWidth='1.55'
+      strokeLinecap='round'
+      strokeLinejoin='round'
       xmlns='http://www.w3.org/2000/svg'
       aria-hidden='true'
       {...props}
     >
-      <path
-        d='M4.32e-07 5.83V3.8C4.32e-07 3.2 0 2.72 0.03 2.33C0.07 1.94 0.14 1.6 0.32 1.28C0.54 0.88 0.88 0.54 1.28 0.32C1.6 0.14 1.94 0.07 2.33 0.03C2.72 0 3.2 5.96e-05 3.8 5.96e-05C4.53 5.93e-05 5.03 -0.01 5.48 0.16C6.47 0.53 6.87 1.45 7.19 2.1L7.48 2.67H10.33C11.025 2.67 11.58 2.67 12.03 2.71C12.48 2.76 12.874 2.86 13.222 3.09C13.495 3.27 13.73 3.51 13.91 3.78C14.14 4.13 14.24 4.52 14.29 4.97C14.33 5.42 14.33 5.98 14.33 6.67C14.33 7.83 14.33 8.73 14.26 9.46C14.19 10.19 14.03 10.78 13.69 11.3C13.41 11.71 13.05 12.07 12.63 12.35C12.11 12.7 11.52 12.85 10.79 12.93C10.07 13 9.16 13 8 13H7.17C5.61 13 4.39 13 3.44 12.87C2.48 12.74 1.72 12.47 1.12 11.877C0.53 11.28 0.26 10.52 0.13 9.56C0 8.61 4.32e-07 7.39 4.32e-07 5.83ZM1 5.83C1 7.42 1 8.56 1.12 9.42C1.23 10.28 1.45 10.79 1.83 11.17C2.21 11.55 2.72 11.77 3.58 11.88C4.44 12 5.58 12 7.17 12H8C9.18 12 10.029 12 10.69 11.93C11.34 11.87 11.75 11.74 12.07 11.52C12.38 11.32 12.65 11.05 12.86 10.74C13.07 10.42 13.2 10.01 13.27 9.35C13.33 8.7 13.33 7.85 13.33 6.67C13.33 5.95 13.33 5.46 13.29 5.07C13.26 4.7 13.19 4.49 13.08 4.33C12.97 4.17 12.83 4.03 12.67 3.92C12.51 3.81 12.3 3.74 11.93 3.71C11.54 3.67 11.046 3.67 10.33 3.67H5.17C4.89 3.67 4.67 3.44 4.67 3.17C4.67 2.89 4.89 2.67 5.17 2.67H6.36L6.3 2.55C5.92 1.8 5.68 1.3 5.12 1.1C4.89 1.01 4.61 1 3.8 1C3.18 1 2.75 1 2.42 1.03C2.1 1.06 1.91 1.11 1.77 1.19C1.53 1.33 1.33 1.53 1.19 1.77C1.11 1.91 1.06 2.1 1.03 2.42C1 2.75 1 3.18 1 3.8V5.83Z'
-        fill='currentColor'
-        stroke='currentColor'
-        strokeWidth='0.3'
-      />
+      <path d='M3.75 17.25A2 2 0 0 1 1.75 15.25V4.25A2 2 0 0 1 3.75 2.25H7L9.5 5.25H14.5A2 2 0 0 1 16.5 7.25V15.25A2 2 0 0 1 14.5 17.25Z' />
     </svg>
   )
 }