Add live dashboard with SSE job events

Expose /jobs, /dedup, and /events routes backed by a new EventBus that
broadcasts job lifecycle and per-job progress over SSE. Serve a static
dashboard from front/ that lists pending and in-progress jobs, streams
agent activity, and shows completed reviews.

Also add migrate-apply/migrate-generate scripts that load .env, update
the Containerfile to ship the front assets and use the apply script, and
refresh the roadmap.

.devcontainer/devcontainer.json

@@ -19,6 +19,9 @@
     },
     "workspaceMount": "source=${localWorkspaceFolder},target=/workspaces/steep,type=bind",
     "workspaceFolder": "/workspaces/steep",
+    "mounts": [
+        "source=/run/user/1000/podman/podman.sock,target=/var/run/docker.sock,type=bind"
+    ],
    	"runArgs": ["--userns=keep-id", "--security-opt", "label=disable"],
     "appPort": [3000]
 }