add eco CLI symlink to setup wizard, document all CLI commands

setup.sh now installs eco → ~/.local/bin/eco (symlink to cli.py).
README.md updated with full eco command reference.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -23,9 +23,9 @@ source .venv/bin/activate && python3 src/main.py
 # WhatsApp bridge
 systemctl --user start echo-whatsapp-bridge
 
-# CLI diagnostics
-./cli.py status
-./cli.py doctor
+# CLI diagnostics (eco = symlink to cli.py, installed by setup.sh)
+eco status
+eco doctor
 
 # Install dependencies
 source .venv/bin/activate && pip install -r requirements.txt