fix: replace 'mcporter list' with 'mcporter config list' to prevent hangs

mcporter list probes all configured servers sequentially, which can hang
indefinitely when servers are slow/offline. mcporter config list reads
config without probing — sufficient for checking if a server is configured.

Affected: doctor checks (4 channels) and install command (2 calls).

Fixes #34

agent_reach/cli.py

@@ -453,7 +453,7 @@ def _install_mcporter():
     # Configure Exa MCP (free, no key needed)
     try:
         r = subprocess.run(
-            ["mcporter", "list"], capture_output=True, text=True, timeout=10
+            ["mcporter", "config", "list"], capture_output=True, text=True, timeout=5
         )
         if "exa" not in r.stdout:
             subprocess.run(
@@ -469,7 +469,7 @@ def _install_mcporter():
     # Check XiaoHongShu MCP (only if server is running)
     try:
         r = subprocess.run(
-            ["mcporter", "list"], capture_output=True, text=True, timeout=10
+            ["mcporter", "config", "list"], capture_output=True, text=True, timeout=5
         )
         if "xiaohongshu" in r.stdout:
             print("  ✅ XiaoHongShu MCP already configured")