fix: add Browser MCP connection diagnostics (#662)

tests/test_mcp_manager.py

@@ -0,0 +1,26 @@
+from src.mcp_manager import _format_mcp_connection_error
+
+
+def test_playwright_mcp_connection_error_includes_install_hint():
+    msg = _format_mcp_connection_error(
+        "Browser (Playwright)",
+        "npx",
+        ["-y", "@playwright/mcp@latest", "--headless"],
+        RuntimeError("package not found"),
+    )
+
+    assert "package not found" in msg
+    assert "Browser MCP could not start" in msg
+    assert "npx -y @playwright/mcp@latest --version" in msg
+    assert "restart Odysseus" in msg
+
+
+def test_generic_mcp_connection_error_preserves_original_error():
+    msg = _format_mcp_connection_error(
+        "Custom MCP",
+        "python",
+        ["server.py"],
+        RuntimeError("boom"),
+    )
+
+    assert msg == "boom"