feat: add HIL diagnostics and meter health handling

tools/hil/flash_pair.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+import argparse
+from pathlib import Path
+
+from hil_common import HilError, load_config, main_guard, new_artifact_dir, pair_ports, pio_command, run_checked
+
+
+def flash_pair(artifact: Path, yes_flash: bool) -> None:
+    if not yes_flash:
+        raise HilError("refusing to flash without --yes-flash")
+    config = load_config()
+    ports = pair_ports(config, "flash")
+    environment = config.get("hil", {}).get("environment", "hil")
+    artifact.mkdir(parents=True, exist_ok=True)
+    run_checked([pio_command(), "run", "-e", environment], log=artifact / "build.log")
+    for port in ports:
+        run_checked([pio_command(), "run", "-e", environment, "-t", "upload", "--upload-port", str(port.device)],
+                    log=artifact / f"flash-{port.name}.log")
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description="Build once and flash the explicitly approved board pair")
+    parser.add_argument("--yes-flash", action="store_true", help="confirm the approved_flash entries for this invocation")
+    parser.add_argument("--artifact-dir")
+    args = parser.parse_args()
+    artifact = Path(args.artifact_dir) if args.artifact_dir else new_artifact_dir("flash")
+    flash_pair(artifact, args.yes_flash)
+    print(f"Flash logs: {artifact}")
+    return 0
+
+
+if __name__ == "__main__":
+    main_guard(main)