Fix gray card icons on Azure docs home page

The Sample Apps and Changelog cards imported file.svg and change.svg,
which have gray (#707385) hardcoded in their fill and are authored at
15px for use as CSS background-images in custom.css. The other cards use
the purple 36x36 *_Color.svg set, so those two rendered gray and
undersized.

Point Changelog at the existing CIPipelines_Color.svg, and add
SampleApps_Color.svg -- the same document artwork as file.svg, recolored
to #4D0DCF and padded to match the set's optical sizing. file.svg and
change.svg are left untouched so the .file-icon and .change-icon CSS
rules keep rendering gray.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: remotesynth

src/assets/images/SampleApps_Color.svg

@@ -12,8 +12,8 @@ import { OverviewCards, HeroCards } from '../../../components/OverviewCards';
 import rocketIcon from '../../../assets/images/GettingStarted_Color.svg';
 import connectionsIcon from '../../../assets/images/Integrations_Color.svg';
 import cubeIcon from '../../../assets/images/LSAWS_Color.svg';
-import fileIcon from '../../../assets/images/file.svg';
-import changeIcon from '../../../assets/images/change.svg';
+import fileIcon from '../../../assets/images/SampleApps_Color.svg';
+import pipelineIcon from '../../../assets/images/CIPipelines_Color.svg';
 
 <HeroCards
   cards={[
@@ -61,7 +61,7 @@ import changeIcon from '../../../assets/images/change.svg';
       title: "Changelog",
       description: "Track Azure emulator updates and release highlights.",
       href: "/azure/changelog",
-      icon: changeIcon.src
+      icon: pipelineIcon.src
     }
   ]}
   client:load