Group data-downloader sensors by DBC CAN messages (#72)

* Group data-downloader sensors by DBC CAN message with subsystem colour coding

- GET /api/sensors/grouped: left-joins DB sensor names against the DBC
  message/signal tree; transmitter node (MOBO, INV, etc.) used as subsystem;
  graceful fallback when no DBC is configured.
- POST /api/dbc/refresh: bust in-memory DBC cache on demand.
- dbc_utils.py: auto-discovers alphabetically newest .dbc in GitHub repo
  (no GITHUB_DBC_PATH required); caches to DATA_DIR/dbc_cache.dbc;
  GITHUB_DBC_PATH accepted as optional pin; falls back to DBC_FILE_PATH.
- config.py: GITHUB_DBC_TOKEN/REPO/BRANCH/PATH and DBC_FILE_PATH settings.
- requirements.txt: cantools + requests.
- docker-compose.yml: DBC env vars wired into data-downloader-api.
- SensorGroupedGrid.tsx: collapsible groups, 8-hue subsystem palette
  (djb2-stable), subsystem + hex CAN ID badges, dark/light mode.
- App.tsx: parallel grouped fetch; grouped grid when DBC available,
  flat fallback otherwise; DBC source tag.
- data-download.tsx: sensor select uses optgroup per message.
- styles.css: message group layout classes.

* Auto-select most recently committed DBC from GitHub repo instead of alphabetically last

* Move DBC env var docs to top-level installer .env.example

* Consolidate into single .env.example under server/installer, remove data-downloader copy

* Keep grouped sensor rows expanded and show decimal CAN IDs

* Provide CI slicks stub for compose image builds

* Stop code-generator image from requiring local anomaly scan script

* Make code-generator FastEmbed prefetch best-effort

Author: wfr-data-acquisition

.github/workflows/docker-build.yml

@@ -93,6 +93,20 @@ jobs:
       run: |
         cd server/installer
         cp .env.example .env
+        mkdir -p .ci-slicks/src/slicks
+        cat > .ci-slicks/pyproject.toml <<'EOF'
+        [project]
+        name = "slicks"
+        version = "0.0.0"
+        [build-system]
+        requires = ["setuptools>=68"]
+        build-backend = "setuptools.build_meta"
+        [tool.setuptools.packages.find]
+        where = ["src"]
+        EOF
+        touch .ci-slicks/README.md
+        echo '__version__ = "0.0.0"' > .ci-slicks/src/slicks/__init__.py
+        echo "SLICKS_HOST_PATH=${PWD}/.ci-slicks" >> .env
 
     - name: Pull pre-built images
       run: |

server/installer/.env.example

@@ -4,12 +4,15 @@
 DBC_FILE_PATH=example.dbc
 
 # ------------------------------------------------------------
-# File uploader — team DBCs from GitHub (optional)
+# Team DBC from GitHub (used by file-uploader and data-downloader)
 # ------------------------------------------------------------
 # Fine-grained PAT or classic PAT with contents:read on Western-Formula-Racing/DBC
 GITHUB_DBC_TOKEN=
 # GITHUB_DBC_REPO=Western-Formula-Racing/DBC
 # GITHUB_DBC_BRANCH=main
+# Data-downloader auto-selects the most recently committed .dbc in the repo.
+# Set GITHUB_DBC_PATH to pin a specific file instead (e.g. WFR26.dbc).
+# GITHUB_DBC_PATH=
 
 # Optional limits for .zip uploads (file-uploader); defaults are generous for team use
 # UPLOAD_ZIP_MAX_ARCHIVE_BYTES=2147483648
@@ -86,10 +89,19 @@ SENSOR_LOOKBACK_DAYS=365
 SCAN_INTERVAL_SECONDS=3600
 
 VITE_API_BASE_URL=http://localhost:8000
-ALLOWED_ORIGINS=http://localhost:3000,http://localhost:5173
+ALLOWED_ORIGINS=http://localhost:3000,http://localhost:5173,https://daq.westernformularacing.org
 
 # End Data Downloader configuration
 
+# ------------------------------------------------------------
+# Health monitor
+# ------------------------------------------------------------
+# All defaults match the standard docker-compose stack; only override if needed.
+# HEALTH_MONITOR_INTERVAL_SECONDS=60
+# HEALTH_MONITOR_TIMESCALEDB_CONTAINER=timescaledb
+# HEALTH_MONITOR_SCANNER_CONTAINER=data-downloader-scanner
+# HEALTH_MONITOR_SCANNER_API_URL=http://data-downloader-api:8000
+
 # ------------------------------------------------------------
 # AI Code Generation — MiniMax (Anthropic-compatible SDK)
 # ------------------------------------------------------------

server/installer/data-downloader/.env.example

@@ -15,6 +15,7 @@
 from pydantic import BaseModel
 
 from backend.config import get_settings
+from backend.dbc_utils import group_sensors_by_message, load_dbc_db, refresh_dbc
 from backend.services import DataDownloaderService
 
 
@@ -124,6 +125,36 @@ def list_sensors(season: str | None = None) -> dict:
     return service.get_sensors(season=season)
 
 
+@app.get("/api/sensors/grouped")
+def list_sensors_grouped(season: str | None = None) -> dict:
+    """
+    Return sensors grouped by their DBC CAN message and transmitter node.
+
+    Each entry in ``messages`` contains only signals that actually have data in
+    TimescaleDB (left-join: DB is truth, DBC is the categorisation guide).
+    Sensors with no matching DBC entry appear in ``ungrouped``.
+
+    Falls back gracefully to ``{"messages": [], "ungrouped": all_sensors}``
+    when no DBC is configured.
+    """
+    sensor_payload = service.get_sensors(season=season)
+    sensor_names: list[str] = sensor_payload.get("sensors", [])
+    db, source = load_dbc_db(settings)
+    grouped = group_sensors_by_message(sensor_names, db)
+    return {
+        "updated_at": sensor_payload.get("updated_at"),
+        "dbc_source": source,
+        **grouped,
+    }
+
+
+@app.post("/api/dbc/refresh")
+def dbc_refresh() -> dict:
+    """Force-reload the DBC from GitHub (or local file). Returns the new source."""
+    source = refresh_dbc(settings)
+    return {"status": "ok", "dbc_source": source}
+
+
 @app.get("/api/scanner-status")
 def scanner_status() -> dict:
     return service.get_scanner_status()

server/installer/data-downloader/backend/app.py

@@ -110,6 +110,25 @@ class Settings(BaseModel):
         default_factory=lambda: _parse_origins(os.getenv("ALLOWED_ORIGINS", "*"))
     )
 
+    # DBC source — GitHub takes priority over local file
+    github_dbc_token: str = Field(
+        default_factory=lambda: os.getenv("GITHUB_DBC_TOKEN", "")
+    )
+    github_dbc_repo: str = Field(
+        default_factory=lambda: os.getenv("GITHUB_DBC_REPO", "Western-Formula-Racing/DBC")
+    )
+    github_dbc_branch: str = Field(
+        default_factory=lambda: os.getenv("GITHUB_DBC_BRANCH", "main")
+    )
+    # Specific file path within the repo, e.g. "WFR26.dbc"
+    github_dbc_path: str = Field(
+        default_factory=lambda: os.getenv("GITHUB_DBC_PATH", "")
+    )
+    # Fallback: local DBC file path
+    dbc_file_path: str | None = Field(
+        default_factory=lambda: os.getenv("DBC_FILE_PATH") or None
+    )
+
 
 @lru_cache(maxsize=1)
 def get_settings() -> Settings: