feat: P0 LLM-readiness — Chrome aislado (9333), tab_select determinista, page_get_text, page_perceive

main.go

@@ -6,6 +6,7 @@ import (
 	"log/slog"
 	"net/http"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/mark3labs/mcp-go/server"
@@ -85,10 +86,16 @@ func registerTools(s *server.MCPServer, d *deps) {
 	registerStorageTools(s, d)
 }
 
-// portOr returns the CDP port, defaulting to 9222 when zero.
+// portOr returns the CDP port, defaulting to 9333 when zero.
+//
+// SECURITY (P0.3): the default is 9333 — the MCP's OWN isolated Chrome — NOT
+// 9222. Port 9222 is the user's daily chromium (CDP enabled globally via
+// /etc/chromium.d/cdp). Defaulting there would let the agent drive the user's
+// banking/email tabs. The MCP operates on its dedicated browser by default;
+// pass port=9222 explicitly only to deliberately attach to the daily browser.
 func portOr(p int) int {
 	if p == 0 {
-		return 9222
+		return 9333
 	}
 	return p
 }
@@ -172,3 +179,28 @@ func truncate(s string, n int) string {
 	}
 	return s[:n] + "\n... [truncated]"
 }
+
+// resolveRoot finds the fn_registry root so we can locate the `fn` binary and
+// the Python venv at runtime. Mirrors registry_mcp's resolveRoot: honors
+// FN_REGISTRY_ROOT, otherwise walks up from cwd looking for registry.db.
+func resolveRoot() (string, error) {
+	if env := os.Getenv("FN_REGISTRY_ROOT"); env != "" {
+		return filepath.Abs(env)
+	}
+	cwd, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+	dir := cwd
+	for {
+		if _, err := os.Stat(filepath.Join(dir, "registry.db")); err == nil {
+			return dir, nil
+		}
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			break
+		}
+		dir = parent
+	}
+	return "", fmt.Errorf("registry.db not found upward from %s", cwd)
+}