platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/routes_cache_helpers_routes.go

@@ -0,0 +1,95 @@
+package app
+
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+func readCurrentRoutesTableLines() ([]string, error) {
+	out, _, code, err := runCommandTimeout(5*time.Second, "ip", "-4", "route", "show", "table", routesTableName())
+	if err != nil && code != 0 {
+		return nil, err
+	}
+	lines := make([]string, 0, 32)
+	for _, raw := range strings.Split(out, "\n") {
+		ln := strings.TrimSpace(raw)
+		if ln == "" {
+			continue
+		}
+		lines = append(lines, ln)
+	}
+	return lines, nil
+}
+
+func detectIfaceFromRoutes(lines []string) string {
+	for _, ln := range lines {
+		fields := strings.Fields(ln)
+		for i := 0; i+1 < len(fields); i++ {
+			if fields[i] == "dev" {
+				return strings.TrimSpace(fields[i+1])
+			}
+		}
+	}
+	return ""
+}
+
+func restoreRouteLine(line string) error {
+	fields := strings.Fields(strings.TrimSpace(line))
+	if len(fields) == 0 {
+		return nil
+	}
+	args := []string{"-4", "route", "replace"}
+	args = append(args, fields...)
+	hasTable := false
+	for i := 0; i+1 < len(fields); i++ {
+		if fields[i] == "table" {
+			hasTable = true
+			break
+		}
+	}
+	if !hasTable {
+		args = append(args, "table", routesTableName())
+	}
+	_, _, code, err := runCommandTimeout(5*time.Second, "ip", args...)
+	if err != nil || code != 0 {
+		if err == nil {
+			err = fmt.Errorf("exit code %d", code)
+		}
+		return err
+	}
+	return nil
+}
+
+func shouldIgnoreRestoreRouteError(line string, err error) bool {
+	ln := strings.ToLower(strings.TrimSpace(line))
+	if strings.Contains(ln, " linkdown") {
+		return true
+	}
+
+	dev := routeLineDevice(ln)
+	if dev != "" && !strings.HasPrefix(ln, "default ") && !ifaceExists(dev) {
+		return true
+	}
+
+	msg := strings.ToLower(strings.TrimSpace(fmt.Sprintf("%v", err)))
+	if strings.HasPrefix(ln, "default ") {
+		return false
+	}
+	if strings.Contains(msg, "cannot find device") ||
+		strings.Contains(msg, "no such device") ||
+		strings.Contains(msg, "network is down") {
+		return true
+	}
+	return false
+}
+
+func routeLineDevice(line string) string {
+	fields := strings.Fields(strings.TrimSpace(line))
+	for i := 0; i+1 < len(fields); i++ {
+		if fields[i] == "dev" {
+			return strings.TrimSpace(fields[i+1])
+		}
+	}
+	return ""
+}