Add route declarations and automatic port allocation to MCP agent

Service definitions can now declare routes per component instead of
manual port mappings:

  [[components.routes]]
  name = "rest"
  port = 8443
  mode = "l4"

The agent allocates free host ports at deploy time and injects
$PORT/$PORT_<NAME> env vars into containers. Backward compatible:
components with old-style ports= work unchanged.

Changes:
- Proto: RouteSpec message, routes + env fields on ComponentSpec
- Servicedef: RouteDef parsing and validation from TOML
- Registry: component_routes table with host_port tracking
- Runtime: Env field on ContainerSpec, -e flag in BuildRunArgs
- Agent: PortAllocator (random 10000-60000, availability check),
  deploy wiring for route→port mapping and env injection

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/registry/components.go

@@ -6,6 +6,15 @@ import (
 	"time"
 )
 
+// Route represents a route entry for a component in the registry.
+type Route struct {
+	Name     string
+	Port     int
+	Mode     string
+	Hostname string
+	HostPort int // agent-assigned host port (0 = not yet allocated)
+}
+
 // Component represents a component in the registry.
 type Component struct {
 	Name          string
@@ -20,6 +29,7 @@ type Component struct {
 	Ports         []string
 	Volumes       []string
 	Cmd           []string
+	Routes        []Route
 	CreatedAt     time.Time
 	UpdatedAt     time.Time
 }
@@ -51,6 +61,9 @@ func CreateComponent(db *sql.DB, c *Component) error {
 	if err := setCmd(tx, c.Service, c.Name, c.Cmd); err != nil {
 		return err
 	}
+	if err := setRoutes(tx, c.Service, c.Name, c.Routes); err != nil {
+		return err
+	}
 
 	return tx.Commit()
 }
@@ -84,6 +97,10 @@ func GetComponent(db *sql.DB, service, name string) (*Component, error) {
 	if err != nil {
 		return nil, err
 	}
+	c.Routes, err = getRoutes(db, service, name)
+	if err != nil {
+		return nil, err
+	}
 
 	return c, nil
 }
@@ -115,6 +132,7 @@ func ListComponents(db *sql.DB, service string) ([]Component, error) {
 		c.Ports, _ = getPorts(db, c.Service, c.Name)
 		c.Volumes, _ = getVolumes(db, c.Service, c.Name)
 		c.Cmd, _ = getCmd(db, c.Service, c.Name)
+		c.Routes, _ = getRoutes(db, c.Service, c.Name)
 
 		components = append(components, c)
 	}
@@ -168,6 +186,9 @@ func UpdateComponentSpec(db *sql.DB, c *Component) error {
 	if err := setCmd(tx, c.Service, c.Name, c.Cmd); err != nil {
 		return err
 	}
+	if err := setRoutes(tx, c.Service, c.Name, c.Routes); err != nil {
+		return err
+	}
 
 	return tx.Commit()
 }
@@ -274,3 +295,85 @@ func getCmd(db *sql.DB, service, component string) ([]string, error) {
 	}
 	return cmd, rows.Err()
 }
+
+// helper: set route definitions (delete + re-insert)
+func setRoutes(tx *sql.Tx, service, component string, routes []Route) error {
+	if _, err := tx.Exec("DELETE FROM component_routes WHERE service = ? AND component = ?", service, component); err != nil {
+		return fmt.Errorf("clear routes %q/%q: %w", service, component, err)
+	}
+	for _, r := range routes {
+		mode := r.Mode
+		if mode == "" {
+			mode = "l4"
+		}
+		name := r.Name
+		if name == "" {
+			name = "default"
+		}
+		if _, err := tx.Exec(
+			"INSERT INTO component_routes (service, component, name, port, mode, hostname, host_port) VALUES (?, ?, ?, ?, ?, ?, ?)",
+			service, component, name, r.Port, mode, r.Hostname, r.HostPort,
+		); err != nil {
+			return fmt.Errorf("insert route %q/%q %q: %w", service, component, name, err)
+		}
+	}
+	return nil
+}
+
+func getRoutes(db *sql.DB, service, component string) ([]Route, error) {
+	rows, err := db.Query(
+		"SELECT name, port, mode, hostname, host_port FROM component_routes WHERE service = ? AND component = ? ORDER BY name",
+		service, component,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("get routes %q/%q: %w", service, component, err)
+	}
+	defer func() { _ = rows.Close() }()
+	var routes []Route
+	for rows.Next() {
+		var r Route
+		if err := rows.Scan(&r.Name, &r.Port, &r.Mode, &r.Hostname, &r.HostPort); err != nil {
+			return nil, err
+		}
+		routes = append(routes, r)
+	}
+	return routes, rows.Err()
+}
+
+// UpdateRouteHostPort updates the agent-assigned host port for a specific route.
+func UpdateRouteHostPort(db *sql.DB, service, component, routeName string, hostPort int) error {
+	res, err := db.Exec(
+		"UPDATE component_routes SET host_port = ? WHERE service = ? AND component = ? AND name = ?",
+		hostPort, service, component, routeName,
+	)
+	if err != nil {
+		return fmt.Errorf("update route host_port %q/%q/%q: %w", service, component, routeName, err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return fmt.Errorf("update route host_port %q/%q/%q: %w", service, component, routeName, sql.ErrNoRows)
+	}
+	return nil
+}
+
+// GetRouteHostPorts returns a map of route name to assigned host port for a component.
+func GetRouteHostPorts(db *sql.DB, service, component string) (map[string]int, error) {
+	rows, err := db.Query(
+		"SELECT name, host_port FROM component_routes WHERE service = ? AND component = ?",
+		service, component,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("get route host ports %q/%q: %w", service, component, err)
+	}
+	defer func() { _ = rows.Close() }()
+	result := make(map[string]int)
+	for rows.Next() {
+		var name string
+		var port int
+		if err := rows.Scan(&name, &port); err != nil {
+			return nil, err
+		}
+		result[name] = port
+	}
+	return result, rows.Err()
+}