fix: preserve shell PATH for managed OpenCode

Restores shell-first PATH resolution for desktop-launched OpenCode
Keeps app PATH entries as fallback
Adds coverage for managed OpenCode PATH merging

packages/web/server/lib/opencode/server-utils-runtime.js

@@ -76,11 +76,6 @@ export const createServerUtilsRuntime = (dependencies) => {
   const buildManagedOpenCodePath = () => {
     const currentPath = process.env.PATH || '';
     const loginShellPath = getLoginShellPath();
-    const home = os.homedir();
-
-    if (pathLooksUserConfigured(currentPath, home, path.delimiter)) {
-      return currentPath;
-    }
 
     return mergePathValues(loginShellPath || '', currentPath, path.delimiter);
   };