restructure config to use Device class directly

Also include device validation

src/commands/ai_hub.py

@@ -4,7 +4,9 @@ from enum import StrEnum
 from pathlib import Path
 from typing import Any
 
+import qai_hub.hub as hub
 import typer
+from qai_hub.client import Device
 
 from src import state as state_ops
 from src.commands.utils import CONFIG_OPT, CONSOLE, load_cfg
@@ -99,6 +101,33 @@ def _model_id_or_state(config_path: str, model_id: str | None, *, quantized: boo
     return resolved
 
 
+def _device_selector(device: Device) -> str:
+    parts: list[str] = []
+    if device.name:
+        parts.append(f"name={device.name!r}")
+    if device.os:
+        parts.append(f"os={device.os!r}")
+    if device.attributes:
+        parts.append(f"attributes={device.attributes!r}")
+    return ", ".join(parts) if parts else "empty selector"
+
+
+def _validate_device(cfg: Config) -> None:
+    device = cfg.aihub.device
+    try:
+        matches = hub.get_devices(name=device.name, os=device.os, attributes=device.attributes)
+    except Exception as e:
+        CONSOLE.print(f"[red]Unable to validate AI Hub device {_device_selector(device)}: {e}[/red]")
+        raise typer.Exit(1)
+
+    if matches:
+        return
+
+    CONSOLE.print(f"[red]AI Hub device not found: {_device_selector(device)}[/red]")
+    CONSOLE.print("Run [bold]qai-hub list-devices[/bold] to see valid device names.")
+    raise typer.Exit(1)
+
+
 def _quantize_step(
     cfg: Config,
     config_path: str,
@@ -156,6 +185,7 @@ def _compile_step(
     prefer_quantized: bool,
 ) -> str:
     st = state_ops.store(config_path)
+    _validate_device(cfg)
     specs = _input_specs(cfg)
 
     model: Any
@@ -184,7 +214,7 @@ def _compile_step(
     try:
         result = aihub_jobs.submit_compile_job(
             model=model,
-            device_name=cfg.aihub.device,
+            device=cfg.aihub.device,
             input_specs=specs,
             target_runtime=cfg.aihub.target_runtime,
             options=cfg.aihub.compile_options,
@@ -214,6 +244,7 @@ def _validate_step(
     model_id: str | None,
     input_name: str | None,
 ) -> str:
+    _validate_device(cfg)
     specs = _input_specs(cfg)
     resolved_model_id = _model_id_or_state(config_path, model_id)
     try:
@@ -247,6 +278,7 @@ def _validate_step(
 
 
 def _profile_step(cfg: Config, config_path: str, model_id: str | None) -> str:
+    _validate_device(cfg)
     resolved_model_id = _model_id_or_state(config_path, model_id)
     try:
         result = aihub_jobs.submit_profile_job(