fix(components): stopPropagation, PlantUML encoding, Tauri 2.x asset URL

GroupAgentsPanel: added e.stopPropagation() on toggleAgent button.
ArchitectureTab: collapsed rawDeflate no-op into single plantumlEncode().
TestingTab: replaced asset://localhost/ with convertFileSrc().

v2/src/lib/components/Workspace/ArchitectureTab.svelte

@@ -154,27 +154,13 @@ package "Backend" {
     }
   }
 
-  // PlantUML text encoder (deflate + base64 variant)
-  // Uses the PlantUML encoding scheme: https://plantuml.com/text-encoding
+  // PlantUML hex encoding — uses the ~h prefix supported by plantuml.com
+  // See: https://plantuml.com/text-encoding
   function plantumlEncode(text: string): string {
-    const data = unescape(encodeURIComponent(text));
-    const compressed = rawDeflate(data);
-    return encode64(compressed);
-  }
-
-  // Minimal raw deflate (store-only for simplicity — works with plantuml.com)
-  function rawDeflate(data: string): string {
-    // For PlantUML server compatibility, we use the ~h hex encoding as fallback
-    // which is simpler and doesn't require deflate
-    return data;
-  }
-
-  // PlantUML base64 encoding (6-bit alphabet: 0-9A-Za-z-_)
-  function encode64(data: string): string {
-    // Use hex encoding prefix for simplicity (supported by PlantUML server)
+    const bytes = unescape(encodeURIComponent(text));
     let hex = '~h';
-    for (let i = 0; i < data.length; i++) {
-      hex += data.charCodeAt(i).toString(16).padStart(2, '0');
+    for (let i = 0; i < bytes.length; i++) {
+      hex += bytes.charCodeAt(i).toString(16).padStart(2, '0');
     }
     return hex;
   }

v2/src/lib/components/Workspace/GroupAgentsPanel.svelte

@@ -146,7 +146,7 @@
                   class="action-btn"
                   class:start={status === 'stopped'}
                   class:stop={status !== 'stopped'}
-                  onclick={() => toggleAgent(agent)}
+                  onclick={(e: MouseEvent) => { e.stopPropagation(); toggleAgent(agent); }}
                   title={status === 'stopped' ? 'Start agent' : 'Stop agent'}
                 >
                   {status === 'stopped' ? '▶' : '■'}

v2/src/lib/components/Workspace/TestingTab.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
   import { onMount, onDestroy } from 'svelte';
+  import { convertFileSrc } from '@tauri-apps/api/core';
   import { listDirectoryChildren, readFileContent, type DirEntry } from '../../adapters/files-bridge';
 
   interface Props {
@@ -150,7 +151,7 @@
         {#if selectedScreenshot}
           <div class="screenshot-preview">
             <img
-              src="asset://localhost/{selectedScreenshot}"
+              src={convertFileSrc(selectedScreenshot)}
               alt="Selenium screenshot"
               class="screenshot-img"
             />