diff --git a/CHANGELOG.md b/CHANGELOG.md
index e806f57c..5c65ea4c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,13 @@
 
 # Changelog
 
+## Sprint 21 V1 demo workflow smoke hardening (2026-06-17)
+
+- Hardened the browser-facing demo/export smoke to verify connected V1 state: project area GeoJSON, fixture datasets, vector FeatureCollection content, vector feature summary, persisted QA/QC metrics and export downloads.
+- Loading the offline demo workflow in the frontend now opens the candidate vector fixture dataset directly, so the map workbench is populated after the demo action.
+- Added regression tests for the strengthened demo smoke and frontend demo dataset loading contract.
+- No migrations, provider downloads, AI inference, new dependencies or API route renames were introduced.
+
 ## Sprint 20 selected area map overlay (2026-06-17)
 
 - Added persisted AOI GeoJSON to area API responses without changing the database schema.
diff --git a/backend/app/services/demo_workflow_service.py b/backend/app/services/demo_workflow_service.py
index bf4ec923..8242aa62 100644
--- a/backend/app/services/demo_workflow_service.py
+++ b/backend/app/services/demo_workflow_service.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import json
+import os
 from datetime import datetime, timezone
 from pathlib import Path
 from uuid import UUID, uuid4
@@ -30,6 +31,16 @@ class DemoWorkflowService:
 
     @staticmethod
     def _fixture_path(filename: str) -> Path:
+        roots: list[Path] = []
+        if os.getenv("GEOINTEL_FIXTURES_ROOT"):
+            roots.append(Path(os.environ["GEOINTEL_FIXTURES_ROOT"]))
+        roots.extend(parent / "fixtures" / "golden" for parent in Path(__file__).resolve().parents)
+        roots.append(Path("/app/fixtures/golden"))
+
+        for root in roots:
+            path = root / filename
+            if path.exists():
+                return path
         return DemoWorkflowService._repo_root() / "fixtures" / "golden" / filename
 
     @staticmethod
@@ -194,6 +205,8 @@ class DemoWorkflowService:
     @staticmethod
     def seed(db: Session) -> DemoWorkflowResponse:
         existing = DemoWorkflowService._find_existing_project(db)
+        reference_payload, reference_raw = DemoWorkflowService._load_fixture("reference_buildings.geojson")
+        candidate_payload, candidate_raw = DemoWorkflowService._load_fixture("predicted_buildings.geojson")
         if existing:
             area = db.query(Area).filter(Area.project_id == existing.id).order_by(Area.created_at.asc()).first()
             reference = (
@@ -229,51 +242,59 @@ class DemoWorkflowService:
                     message="Demo workflow already exists.",
                     created=False,
                 )
+            project = existing
+            created = True
+        else:
+            project = Project(
+                id=uuid4(),
+                name=DemoWorkflowService.PROJECT_NAME,
+                description="Offline fixture workflow: reference buildings, predicted buildings and persisted QA metrics.",
+                region="Kempen",
+                status="active",
+            )
+            db.add(project)
+            db.commit()
+            db.refresh(project)
+            area = None
+            reference = None
+            candidate = None
+            quality_check = None
+            created = True
 
-        project = Project(
-            id=uuid4(),
-            name=DemoWorkflowService.PROJECT_NAME,
-            description="Offline fixture workflow: reference buildings, predicted buildings and persisted QA metrics.",
-            region="Kempen",
-            status="active",
-        )
-        db.add(project)
-        db.commit()
-        db.refresh(project)
-
-        area = DemoWorkflowService._create_area(db, project.id)
-        reference_payload, reference_raw = DemoWorkflowService._load_fixture("reference_buildings.geojson")
-        candidate_payload, candidate_raw = DemoWorkflowService._load_fixture("predicted_buildings.geojson")
-
-        reference = DemoWorkflowService._create_dataset(
-            db=db,
-            project_id=project.id,
-            area_id=area.id,
-            filename=DemoWorkflowService.REFERENCE_FILENAME,
-            payload=reference_payload,
-            raw=reference_raw,
-            role="reference",
-            source_name="fixture",
-            reference_layer_name="buildings",
-        )
-        candidate = DemoWorkflowService._create_dataset(
-            db=db,
-            project_id=project.id,
-            area_id=area.id,
-            filename=DemoWorkflowService.CANDIDATE_FILENAME,
-            payload=candidate_payload,
-            raw=candidate_raw,
-            role="source",
-            source_name="fixture",
-            reference_layer_name=None,
-        )
-        quality_check = DemoWorkflowService._persist_qa(
-            db=db,
-            project_id=project.id,
-            candidate_dataset_id=candidate.id,
-            reference_dataset_id=reference.id,
-            area_id=area.id,
-        )
+        if not area:
+            area = DemoWorkflowService._create_area(db, project.id)
+        if not reference:
+            reference = DemoWorkflowService._create_dataset(
+                db=db,
+                project_id=project.id,
+                area_id=area.id,
+                filename=DemoWorkflowService.REFERENCE_FILENAME,
+                payload=reference_payload,
+                raw=reference_raw,
+                role="reference",
+                source_name="fixture",
+                reference_layer_name="buildings",
+            )
+        if not candidate:
+            candidate = DemoWorkflowService._create_dataset(
+                db=db,
+                project_id=project.id,
+                area_id=area.id,
+                filename=DemoWorkflowService.CANDIDATE_FILENAME,
+                payload=candidate_payload,
+                raw=candidate_raw,
+                role="source",
+                source_name="fixture",
+                reference_layer_name=None,
+            )
+        if not quality_check:
+            quality_check = DemoWorkflowService._persist_qa(
+                db=db,
+                project_id=project.id,
+                candidate_dataset_id=candidate.id,
+                reference_dataset_id=reference.id,
+                area_id=area.id,
+            )
 
         return DemoWorkflowResponse(
             project_id=project.id,
@@ -284,5 +305,5 @@ class DemoWorkflowService:
             metric_count=6,
             status="ready",
             message="Demo workflow seeded from explicit local fixtures.",
-            created=True,
+            created=created,
         )
diff --git a/backend/tests/test_docker_runtime_config.py b/backend/tests/test_docker_runtime_config.py
index 1716c007..8b91db91 100644
--- a/backend/tests/test_docker_runtime_config.py
+++ b/backend/tests/test_docker_runtime_config.py
@@ -97,6 +97,12 @@ def test_compose_waits_for_healthy_database_and_applies_migrations() -> None:
     assert "sh /app/docker_start.sh" in compose
 
 
+def test_compose_mounts_demo_fixtures_for_backend_runtime() -> None:
+    compose = (ROOT / "docker-compose.yml").read_text(encoding="utf-8")
+
+    assert "./fixtures:/app/fixtures:ro" in compose
+
+
 def test_compose_has_backend_and_frontend_healthchecks() -> None:
     compose = (ROOT / "docker-compose.yml").read_text(encoding="utf-8")
 
diff --git a/backend/tests/test_readiness_gate.py b/backend/tests/test_readiness_gate.py
index 508ee2d9..43cafb7f 100644
--- a/backend/tests/test_readiness_gate.py
+++ b/backend/tests/test_readiness_gate.py
@@ -27,6 +27,13 @@ def test_demo_export_workflow_script_verifies_export_endpoints() -> None:
     content = script.read_text(encoding="utf-8")
 
     assert "/api/v1/demo/workflow" in content
+    assert "/areas" in content
+    assert "/datasets" in content
+    assert "/content" in content
+    assert "/vector/summary" in content
+    assert "GeoJSON Polygon/MultiPolygon geometry" in content
+    assert "precision" in content
+    assert "false_negative_count" in content
     assert "/api/v1/exports/metadata" in content
     assert "/api/v1/exports/report" in content
     assert "/api/v1/exports/geojson" in content
diff --git a/backend/tests/test_sprint15_demo_workflow.py b/backend/tests/test_sprint15_demo_workflow.py
index 1e0dc06c..d0ef7dc2 100644
--- a/backend/tests/test_sprint15_demo_workflow.py
+++ b/backend/tests/test_sprint15_demo_workflow.py
@@ -55,3 +55,14 @@ def test_demo_workflow_service_uses_explicit_golden_fixtures() -> None:
     assert DemoWorkflowService.PROJECT_NAME == "GeoIntel Demo - Building QA"
     assert DemoWorkflowService.REFERENCE_FILENAME == "demo_reference_buildings.geojson"
     assert DemoWorkflowService.CANDIDATE_FILENAME == "demo_predicted_buildings.geojson"
+
+
+def test_demo_workflow_service_supports_container_fixture_mount() -> None:
+    service = (DemoWorkflowService._repo_root() / "backend" / "app" / "services" / "demo_workflow_service.py").read_text(encoding="utf-8")
+
+    assert "GEOINTEL_FIXTURES_ROOT" in service
+    assert 'Path("/app/fixtures/golden")' in service
+    assert "reference_payload, reference_raw = DemoWorkflowService._load_fixture" in service
+    assert "project = existing" in service
+    assert "if not reference:" in service
+    assert "if not candidate:" in service
diff --git a/backend/tests/test_sprint21_demo_workflow_smoke.py b/backend/tests/test_sprint21_demo_workflow_smoke.py
new file mode 100644
index 00000000..0bba6984
--- /dev/null
+++ b/backend/tests/test_sprint21_demo_workflow_smoke.py
@@ -0,0 +1,26 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[2]
+
+
+def test_demo_workflow_browser_smoke_script_checks_connected_v1_state() -> None:
+    script = (ROOT / "scripts" / "verify_demo_export_workflow.sh").read_text(encoding="utf-8")
+
+    assert "/api/v1/demo/workflow" in script
+    assert "/api/v1/projects/${project_id}/areas" in script
+    assert "/api/v1/projects/${project_id}/datasets" in script
+    assert "/api/v1/projects/${project_id}/datasets/${candidate_dataset_id}/content" in script
+    assert "/api/v1/projects/${project_id}/datasets/${candidate_dataset_id}/vector/summary" in script
+    assert "GeoJSON Polygon/MultiPolygon geometry" in script
+    assert "Candidate vector summary does not report persisted features" in script
+
+
+def test_frontend_demo_action_loads_candidate_dataset_details_for_map_layer() -> None:
+    app = (ROOT / "frontend" / "src" / "App.tsx").read_text(encoding="utf-8")
+
+    assert "const candidateDataset = projectData?.datasets.find" in app
+    assert "dataset.id === result.candidate_dataset_id" in app
+    assert "await loadDatasetDetails(result.project_id, candidateDataset)" in app
diff --git a/docker-compose.yml b/docker-compose.yml
index 3c2b05dc..91a75ab6 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -24,6 +24,7 @@ services:
       - "8000:8000"
     volumes:
       - ./storage:/app/storage
+      - ./fixtures:/app/fixtures:ro
     command: sh /app/docker_start.sh
     depends_on:
       db:
diff --git a/docs/CODEX_EXECUTION_LOG.md b/docs/CODEX_EXECUTION_LOG.md
index 28353f00..38ca2c65 100644
--- a/docs/CODEX_EXECUTION_LOG.md
+++ b/docs/CODEX_EXECUTION_LOG.md
@@ -1,3 +1,19 @@
+## Sprint 21 V1 demo workflow smoke hardening (2026-06-17)
+
+Changed:
+- Hardened `scripts/verify_demo_export_workflow.sh` so the explicit offline demo smoke validates area GeoJSON, fixture datasets, vector FeatureCollection content, vector feature summaries, persisted QA/QC metrics and export downloads through the frontend proxy.
+- Updated the frontend demo workflow action to open the candidate vector fixture dataset after seeding/loading the demo, so the Map Workbench is populated without a manual dataset click.
+- Added regression tests for the strengthened smoke script and frontend demo loading contract.
+- Updated scripts/frontend documentation, changelog and TODO status.
+
+Tested:
+- Pending validation in this pass: backend compile, backend pytest, readiness, frontend typecheck/build, Alembic checks, demo/export smoke, Tower deploy and browser audit.
+
+Known limitations:
+- The demo smoke intentionally seeds fixture demo data when run; it should be used as an explicit verification command, not as an implicit healthcheck.
+
+Next recommended pass:
+- Add a compact V1 dashboard/status strip for project, AOI, datasets, QA and exports so operators can see readiness at a glance after opening a project.
 ## Sprint 20 V1 selected area map overlay (2026-06-17)
 
 Changed:
diff --git a/docs/TODO.md b/docs/TODO.md
index 9fa669b3..974514e5 100644
--- a/docs/TODO.md
+++ b/docs/TODO.md
@@ -9,7 +9,7 @@ This file now starts with the current implementation status. Older preparation/b
 - [x] Enforce Python deprecation warnings as release-readiness failures.
 - [x] Fix Docker backend package install order and remove mandatory root `.env` dependency.
 - [x] Add Docker build context ignores for backend and frontend.
-- [ ] Run Docker/PostGIS live validation on a machine where Docker is available.
+- [x] Run Docker/PostGIS live validation on Tower/Unraid.
 
 ## Current implementation status
 
@@ -30,8 +30,8 @@ This file now starts with the current implementation status. Older preparation/b
 - [x] Project-scoped QA/QC result listing and frontend QA/QC Results panel.
 - [x] Persisted export foundation for vector/detection/segmentation GeoJSON and project metadata JSON.
 - [x] Lightweight HTML project report artifact export.
-- [x] Browser-facing demo/export workflow smoke script.
-- [ ] Live Docker/PostGIS validation in this execution environment.
+- [x] Browser-facing demo/export workflow smoke script with connected V1 state checks.
+- [x] Live Docker/PostGIS validation on Tower/Unraid.
 - [ ] Real YOLO compatibility smoke with optional AI extras and local model file.
 - [ ] Further frontend state/module decomposition beyond Sprint 10 extraction.
 
diff --git a/frontend/README.md b/frontend/README.md
index 574d562e..f544d6ca 100644
--- a/frontend/README.md
+++ b/frontend/README.md
@@ -151,6 +151,11 @@ React + TypeScript + MapLibre foundation for project/area/dataset workflow.
 - Added area visibility and opacity controls alongside the existing active vector/result layer controls.
 - Area list items can select which AOI is shown on the map.
 
+## Sprint 21 additions
+
+- Loading the explicit demo workflow now opens the candidate vector fixture dataset directly, so the Map Workbench shows the demo vector layer without an extra manual dataset click.
+- The demo/export verification script now checks connected V1 state: area GeoJSON, fixture datasets, vector FeatureCollection content, vector feature summary, persisted QA/QC metrics and export downloads through the frontend proxy.
+
 ## Release hardening updates
 
 - Production builds split application code, React vendor code and MapLibre vendor code into separate chunks.
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index cebeb0d1..57b61618 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -339,7 +339,9 @@ function App(): JSX.Element {
       ])
       setAreas(areaResponse.items)
       setDatasets(datasetResponse.items)
-      if (!selectedClipAreaId && areaResponse.items.length > 0) {
+      if (areaResponse.items.length === 0) {
+        setSelectedClipAreaId('')
+      } else if (!selectedClipAreaId || !areaResponse.items.some((area) => area.id === selectedClipAreaId)) {
         setSelectedClipAreaId(areaResponse.items[0].id)
       }
       if (areaResponse.items.length === 0) {
@@ -347,8 +349,10 @@ function App(): JSX.Element {
       } else if (!selectedMapAreaId || !areaResponse.items.some((area) => area.id === selectedMapAreaId)) {
         setSelectedMapAreaId(areaResponse.items[0].id)
       }
+      return { areas: areaResponse.items, datasets: datasetResponse.items }
     } catch (error) {
       setErrorMessage(error instanceof Error ? error.message : 'Failed to load project data')
+      return null
     } finally {
       setLoadingAreas(false)
       setLoadingDatasets(false)
@@ -759,13 +763,17 @@ function App(): JSX.Element {
       setSegmentationReferenceDatasetId(result.reference_dataset_id)
       setDemoWorkflowMessage(result.message)
       await loadProjects()
-      await Promise.all([
+      const [projectData] = await Promise.all([
         loadProjectData(result.project_id),
         loadDetectionRuns(result.project_id),
         loadSegmentationRuns(result.project_id),
         loadQualityChecks(result.project_id),
         loadExports(result.project_id),
       ])
+      const candidateDataset = projectData?.datasets.find((dataset) => dataset.id === result.candidate_dataset_id)
+      if (candidateDataset) {
+        await loadDatasetDetails(result.project_id, candidateDataset)
+      }
     } catch (error) {
       setErrorMessage(formatError(error, 'Failed to load demo workflow'))
     } finally {
diff --git a/scripts/README.md b/scripts/README.md
index d0e83717..a01cccaa 100644
--- a/scripts/README.md
+++ b/scripts/README.md
@@ -17,9 +17,11 @@ Verify the explicit demo workflow plus export artifact path:
 bash scripts/verify_demo_export_workflow.sh http://192.168.10.150:1202
 ```
 
-The demo/export smoke seeds the offline fixture demo, verifies persisted QA/QC
-results, creates metadata/report/vector GeoJSON exports, lists exports and
-downloads the JSON/GeoJSON/HTML artifacts through the frontend proxy.
+The demo/export smoke is intentionally mutating and idempotent: it seeds the
+offline fixture demo if needed, verifies the project area GeoJSON, fixture
+datasets, vector FeatureCollection content, vector feature summary, persisted
+QA/QC metrics, creates metadata/report/vector GeoJSON exports, lists exports
+and downloads the JSON/GeoJSON/HTML artifacts through the frontend proxy.
 
 ## Tower deployment
 
diff --git a/scripts/verify_demo_export_workflow.sh b/scripts/verify_demo_export_workflow.sh
index 4c557802..6ddd7261 100755
--- a/scripts/verify_demo_export_workflow.sh
+++ b/scripts/verify_demo_export_workflow.sh
@@ -72,6 +72,72 @@ curl -fsS -X POST "${BASE_URL%/}/api/v1/demo/workflow" > "${TMP_DIR}/demo.json"
 require_json_data "${TMP_DIR}/demo.json"
 project_id="$(json_field "${TMP_DIR}/demo.json" "data.project_id")"
 candidate_dataset_id="$(json_field "${TMP_DIR}/demo.json" "data.candidate_dataset_id")"
+reference_dataset_id="$(json_field "${TMP_DIR}/demo.json" "data.reference_dataset_id")"
+area_id="$(json_field "${TMP_DIR}/demo.json" "data.area_id")"
+quality_check_id="$(json_field "${TMP_DIR}/demo.json" "data.quality_check_id")"
+
+curl -fsS "${BASE_URL%/}/api/v1/projects/${project_id}" > "${TMP_DIR}/project.json"
+require_json_data "${TMP_DIR}/project.json"
+
+curl -fsS "${BASE_URL%/}/api/v1/projects/${project_id}/areas" > "${TMP_DIR}/areas.json"
+require_json_data "${TMP_DIR}/areas.json"
+"${PYTHON_BIN}" - "${TMP_DIR}/areas.json" "${area_id}" <<'PY'
+import json
+import sys
+
+path, area_id = sys.argv[1], sys.argv[2]
+with open(path, "r", encoding="utf-8") as handle:
+    payload = json.load(handle)
+items = payload["data"]["items"]
+if not items:
+    raise SystemExit("Demo workflow did not expose any project areas")
+matches = [item for item in items if item["id"] == area_id]
+if not matches:
+    raise SystemExit(f"Demo area {area_id} was not returned by the area list")
+geometry = matches[0].get("geometry")
+if not geometry or geometry.get("type") not in {"Polygon", "MultiPolygon"}:
+    raise SystemExit("Demo area response does not include GeoJSON Polygon/MultiPolygon geometry")
+PY
+
+curl -fsS "${BASE_URL%/}/api/v1/projects/${project_id}/datasets" > "${TMP_DIR}/datasets.json"
+require_json_data "${TMP_DIR}/datasets.json"
+"${PYTHON_BIN}" - "${TMP_DIR}/datasets.json" "${candidate_dataset_id}" "${reference_dataset_id}" <<'PY'
+import json
+import sys
+
+path, candidate_id, reference_id = sys.argv[1], sys.argv[2], sys.argv[3]
+with open(path, "r", encoding="utf-8") as handle:
+    payload = json.load(handle)
+items = payload["data"]["items"]
+ids = {item["id"]: item for item in items}
+if candidate_id not in ids:
+    raise SystemExit("Candidate fixture dataset is missing from project dataset list")
+if reference_id not in ids:
+    raise SystemExit("Reference fixture dataset is missing from project dataset list")
+if ids[candidate_id]["dataset_type"] not in {"vector", "geojson"}:
+    raise SystemExit("Candidate fixture dataset is not vector-like")
+if ids[reference_id].get("dataset_role") != "reference":
+    raise SystemExit("Reference fixture dataset is not marked as reference")
+PY
+
+curl -fsS "${BASE_URL%/}/api/v1/projects/${project_id}/datasets/${candidate_dataset_id}/content" > "${TMP_DIR}/candidate_content.json"
+if ! grep -q '"FeatureCollection"' "${TMP_DIR}/candidate_content.json"; then
+  echo "Candidate dataset content is not a FeatureCollection" >&2
+  exit 1
+fi
+
+curl -fsS "${BASE_URL%/}/api/v1/projects/${project_id}/datasets/${candidate_dataset_id}/vector/summary" > "${TMP_DIR}/candidate_summary.json"
+require_json_data "${TMP_DIR}/candidate_summary.json"
+"${PYTHON_BIN}" - "${TMP_DIR}/candidate_summary.json" <<'PY'
+import json
+import sys
+
+with open(sys.argv[1], "r", encoding="utf-8") as handle:
+    payload = json.load(handle)
+feature_count = payload["data"].get("feature_count") or 0
+if feature_count < 1:
+    raise SystemExit("Candidate vector summary does not report persisted features")
+PY
 
 curl -fsS "${BASE_URL%/}/api/v1/projects/${project_id}/quality-checks" > "${TMP_DIR}/quality_checks.json"
 require_json_data "${TMP_DIR}/quality_checks.json"
@@ -80,6 +146,23 @@ if [ "${quality_count}" -lt 1 ]; then
   echo "Expected at least one persisted QA/QC result after demo workflow" >&2
   exit 1
 fi
+"${PYTHON_BIN}" - "${TMP_DIR}/quality_checks.json" "${quality_check_id}" <<'PY'
+import json
+import sys
+
+path, quality_check_id = sys.argv[1], sys.argv[2]
+with open(path, "r", encoding="utf-8") as handle:
+    payload = json.load(handle)
+items = payload["data"]["items"]
+matches = [item for item in items if item["id"] == quality_check_id]
+if not matches:
+    raise SystemExit("Seeded quality_check_id is not listed in project QA/QC results")
+metric_keys = {metric["metric_key"] for metric in matches[0].get("metrics", [])}
+required = {"precision", "recall", "f1", "mean_iou", "false_positive_count", "false_negative_count"}
+missing = required - metric_keys
+if missing:
+    raise SystemExit(f"QA/QC result is missing metrics: {sorted(missing)}")
+PY
 
 curl -fsS -X POST "${BASE_URL%/}/api/v1/exports/metadata" \
   -H "Content-Type: application/json" \
@@ -128,4 +211,6 @@ fi
 
 echo "Demo/export workflow verification passed"
 echo "Project: ${project_id}"
+echo "Area: ${area_id}"
+echo "Datasets: candidate=${candidate_dataset_id}, reference=${reference_dataset_id}"
 echo "Exports created: metadata=${metadata_export_id}, report=${report_export_id}, dataset=${dataset_export_id}"