devshells.clan-app: require less environment variables

also sort shellHook by component

pkgs/clan-app/process-compose.yaml

@@ -10,15 +10,15 @@ processes:
       direnv exec . npm install
       direnv exec . vite
     ready_log_line: "VITE"
-    working_dir: "$PKG_ROOT_WEBVIEW_UI/app"
+    working_dir: "$PRJ_ROOT/pkgs/clan-app/webview-ui/app"
 
   clan-app:
     command: |
       direnv allow
-      direnv exec . clan-app --debug --content-uri http://localhost:3000
+      direnv exec . ./bin/clan-app --debug --content-uri http://localhost:3000
     depends_on:
       webview-ui:
         condition: "process_log_ready"
     is_foreground: true
     ready_log_line: "Debug mode enabled"
-    working_dir: "$PKG_ROOT_CLAN_APP"
+    working_dir: "$PRJ_ROOT/pkgs/clan-app"