feat(docker): routes de gestion des stacks (settings/roots/scan/list/enable)

Rend le flux Docker déclenchable via l'API (prérequis SJ-5/SJ-6) :
- GET  /machines/:id/docker/settings — settings + racines Compose
- POST /machines/:id/docker/roots    — déclare/active les racines à scanner
- POST /machines/:id/docker/scan     — scan passif (background, WS)
- GET  /machines/:id/docker/stacks   — liste stacks + services
- PATCH /machines/:id/docker/stacks/:stackId — cycle candidate→enabled→ignored

dockerScan: getDockerSettings, listStacks, setStackStatus. Les actions
pull-check/apply/down restent réservées aux stacks enabled.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server/routes/index.ts

@@ -3,6 +3,7 @@ import { Hono } from "hono";
 import { machinesRoutes } from "./machines.js";
 import { actionsRoutes } from "./actions.js";
 import { actionRequestsRoutes } from "./actionRequests.js";
+import { dockerRoutes } from "./docker.js";
 import { dbRoutes } from "./db.js";
 import { getServerCapabilities } from "../services/capabilities.js";
 import { getSystemMetrics, getSystemStatus } from "../services/system.js";
@@ -14,4 +15,5 @@ api.get("/system/metrics", (c) => c.json(getSystemMetrics()));
 api.route("/system/db", dbRoutes);
 api.route("/machines", machinesRoutes);
 api.route("/machines", actionsRoutes);
+api.route("/machines", dockerRoutes);
 api.route("/", actionRequestsRoutes);