process-compose: simplify environment

we already are in the right devshell for clan-app, so we no longer need
direnv exec. Instead of depending on implicit enviroment variables we
can run change the directory based on the git root as this is easier to
read and follow.

pkgs/clan-app/process-compose.yaml

@@ -1,24 +1,20 @@
 version: "0.5"
 
-env_cmds:
-  PRJ_ROOT: "git rev-parse --show-toplevel"
-
 processes:
   webview-ui:
     command: |
+      cd $(git rev-parse --show-toplevel)/pkgs/clan-app/webview-ui/app
       direnv allow
       direnv exec . npm install
       direnv exec . vite
     ready_log_line: "VITE"
-    working_dir: "$PRJ_ROOT/pkgs/clan-app/webview-ui/app"
 
   clan-app:
     command: |
-      direnv allow
-      direnv exec . ./bin/clan-app --debug --content-uri http://localhost:3000
+      cd $(git rev-parse --show-toplevel)/pkgs/clan-app
+      ./bin/clan-app --debug --content-uri http://localhost:3000
     depends_on:
       webview-ui:
         condition: "process_log_ready"
     is_foreground: true
     ready_log_line: "Debug mode enabled"
-    working_dir: "$PRJ_ROOT/pkgs/clan-app"