cnn: re-version nangate45 and sky130hd images after rebase

Cnn branch was rebased onto main, so the per-design SHAs moved:
  nangate45  d4cd94c -> 70a8889
  sky130hd   948486d -> 846c7ba

Image content is identical (k8s artifacts unchanged); only the
versioned filenames + data-commit attributes + commit links shift.
asap7 stays at 5d40700 (commit was already on main).

Author: mguthaus

figures/cnn_nangate45_d4cd94cc.png figures/cnn_nangate45_70a8889b.pngfigures/cnn_nangate45_d4cd94cc.png renamed to figures/cnn_nangate45_70a8889b.png

@@ -384,8 +384,8 @@ <h2><a href="https://github.com/NNgen/nngen">CNN</a></h2>
         <div class="design-image">
           <div class="design-thumbs">
             <a class="thumb-link" href="figures/cnn_asap7_5d40700b.png"><img src="figures/thumbs/cnn_asap7_5d40700b.jpg" alt="CNN asap7 final"><span class="thumb-label asap7">asap7</span></a>
-            <a class="thumb-link" href="figures/cnn_nangate45_d4cd94cc.png"><img src="figures/thumbs/cnn_nangate45_d4cd94cc.jpg" alt="CNN nangate45 final"><span class="thumb-label nangate45">nangate45</span></a>
-            <a class="thumb-link" href="figures/cnn_sky130hd_948486d6.png"><img src="figures/thumbs/cnn_sky130hd_948486d6.jpg" alt="CNN sky130hd final"><span class="thumb-label sky130hd">sky130hd</span></a>
+            <a class="thumb-link" href="figures/cnn_nangate45_70a8889b.png"><img src="figures/thumbs/cnn_nangate45_70a8889b.jpg" alt="CNN nangate45 final"><span class="thumb-label nangate45">nangate45</span></a>
+            <a class="thumb-link" href="figures/cnn_sky130hd_846c7ba9.png"><img src="figures/thumbs/cnn_sky130hd_846c7ba9.jpg" alt="CNN sky130hd final"><span class="thumb-label sky130hd">sky130hd</span></a>
           </div>
         </div>
         <div class="design-info">

figures/cnn_sky130hd_948486d6.png figures/cnn_sky130hd_846c7ba9.pngfigures/cnn_sky130hd_948486d6.png renamed to figures/cnn_sky130hd_846c7ba9.png

@@ -755,7 +755,7 @@ <h1>Build Results</h1>
             <td>28.930</td>
             <td><a href="https://github.com/VLSIDA/HighTide/commit/f4024825">f4024825</a></td>
             </tr>
-          <tr data-design="cnn" data-platform="nangate45" data-commit="d4cd94cc">
+          <tr data-design="cnn" data-platform="nangate45" data-commit="70a8889b">
             <td><span class="platform-badge badge-nangate45">nangate45</span></td>
             <td>cnn</td>
             <td>19255100.0</td>
@@ -773,7 +773,7 @@ <h1>Build Results</h1>
             <td>0.49</td>
             <td>156.276</td>
             <td>68.760</td>
-            <td><a href="https://github.com/VLSIDA/HighTide/commit/d4cd94cc">d4cd94cc</a></td>
+            <td><a href="https://github.com/VLSIDA/HighTide/commit/70a8889b">70a8889b</a></td>
             </tr>
           <tr data-design="coralnpu" data-platform="nangate45" data-commit="643ba623">
             <td><span class="platform-badge badge-nangate45">nangate45</span></td>
@@ -1115,7 +1115,7 @@ <h1>Build Results</h1>
             <td>43.704</td>
             <td><a href="https://github.com/VLSIDA/HighTide/commit/0f878ac5">0f878ac5</a></td>
             </tr>
-          <tr data-design="cnn" data-platform="sky130hd" data-commit="948486d6">
+          <tr data-design="cnn" data-platform="sky130hd" data-commit="846c7ba9">
             <td><span class="platform-badge badge-sky130hd">sky130hd</span></td>
             <td>cnn</td>
             <td>50176000.0</td>
@@ -1133,7 +1133,7 @@ <h1>Build Results</h1>
             <td>0.11</td>
             <td>313.448</td>
             <td>176.300</td>
-            <td><a href="https://github.com/VLSIDA/HighTide/commit/948486d6">948486d6</a></td>
+            <td><a href="https://github.com/VLSIDA/HighTide/commit/846c7ba9">846c7ba9</a></td>
             </tr>
           <tr data-design="coralnpu" data-platform="sky130hd" data-commit="6d6f2dc2">
             <td><span class="platform-badge badge-sky130hd">sky130hd</span></td>