fix(agent): advertise USRP auto-select (identifier=None), not name=

The CLI get_sdr_device path can only open a USB USRP via auto-select: its
_create_device_dict matches the identifier against raw device-dict values,
but common.py prepends "addr="/"name=" before handing it over, so no prefixed
identifier ever matches (this is also why addr=192.168.3.1 failed to match the
B210). Advertising name=<name> was therefore unusable.

detect_devices() now advertises a single USRP entry with identifier=None
(auto-select the sole device), labelled with the serial(s) found. The hub
forwards None, so the agent opens USRP() and picks the attached B210.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ria_toolkit_oss/agent/hardware.py

@@ -84,24 +84,26 @@ def _enumerate_usrp() -> list[dict] | None:
         logger.debug("USRP enumeration failed: %s", exc)
         return None
 
-    entries: list[dict] = []
-    for dev in found:
-        serial = dev.get("serial") or ""
-        name = dev.get("name") or ""
-        product = dev.get("product") or dev.get("type") or "USRP"
-        # parse_ident only round-trips IP (bare) or ``name=`` — UHD has no
-        # serial= addressing here, so prefer name; otherwise auto-select (None).
-        identifier = f"name={name}" if name else None
-        suffix = serial or name or product
-        entries.append(
-            {
-                "device": "usrp",
-                "identifier": identifier,
-                "label": _label_for("usrp", suffix),
-                "connected": True,
-            }
-        )
-    return entries
+    if not found:
+        return []
+
+    # Addressing reality for the CLI get_sdr_device path: its USRP
+    # _create_device_dict matches the identifier against *raw* device values,
+    # but common.py prepends "addr="/"name=" before handing it over — so no
+    # prefixed identifier ever matches. The only reliable open for a USB USRP
+    # (B2x0) is auto-select (identifier=None → first device found). Networked
+    # USRPs addressed by IP would need a separate fix and aren't enumerated
+    # distinctly here. So advertise one auto-select entry, labelled with the
+    # serial(s) we saw so the operator still knows what's attached.
+    labels = [dev.get("serial") or dev.get("name") or dev.get("product") or "USRP" for dev in found]
+    return [
+        {
+            "device": "usrp",
+            "identifier": None,
+            "label": _label_for("usrp", ", ".join(labels)),
+            "connected": True,
+        }
+    ]
 
 
 # Device types we can cheaply enumerate into concrete instances. Anything not