feat: get_channel_scan() + push_radio_channel() in OpenWrtWirelessMixin

get_channel_scan(mode='active'|'passive'):
- Discovers AP-mode interfaces via 'iw dev'
- Runs 'iw dev <iface> scan [passive]' on each AP interface
- Parses BSS blocks: BSSID, SSID, frequency, channel, signal, channel
  width (HT/VHT/HE), band (2.4/5/6 GHz)
- Returns dict[iface → list[ChannelScanEntryDict]]

push_radio_channel(radio, channel):
- Sets channel via 'uci set wireless.<radio>.channel=<ch|auto>'
- Commits and reloads: 'uci commit wireless && wifi reload'
- channel=0 writes 'auto'

Tests: 19 new unit tests covering parse logic, active/passive flag,
AP-only interface filtering, 6 GHz band detection, push command order.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/unit/test_driver.py

@@ -833,3 +833,267 @@ class TestGetNetworkInstances:
         )
         for inst in driver.get_network_instances().values():
             assert set(inst.keys()) >= {"name", "type", "state", "interfaces"}
+
+
+# ---------------------------------------------------------------------------
+# Sample data for get_channel_scan()
+# ---------------------------------------------------------------------------
+
+IW_DEV_OUT = """\
+phy#0
+\tInterface wlan0
+\t\tifindex 4
+\t\twdev 0x1
+\t\taddr aa:bb:cc:dd:ee:f0
+\t\tssid HomeNet
+\t\ttype AP
+\t\tchannel 6 (2437 MHz), width: 20 MHz, center1: 2437 MHz
+phy#1
+\tInterface wlan1
+\t\tifindex 5
+\t\twdev 0x2
+\t\taddr aa:bb:cc:dd:ee:f1
+\t\tssid HomeNet
+\t\ttype AP
+\t\tchannel 36 (5180 MHz), width: 80 MHz, center1: 5210 MHz
+\tInterface wlan2
+\t\tifindex 6
+\t\twdev 0x3
+\t\taddr aa:bb:cc:dd:ee:f2
+\t\tssid GuestNet
+\t\ttype managed
+"""
+
+# Minimal iw scan output for wlan0 (2.4 GHz AP, ch 6 + ch 1)
+IW_SCAN_WLAN0 = """\
+BSS aa:bb:cc:dd:01:ff(on wlan0)
+\tfreq: 2437
+\tsignal: -72.00 dBm
+\tSSID: NeighborNet1
+\tHT operation:
+\t\t * primary channel: 6
+\t\t * secondary channel offset: no secondary
+\t\t * STA channel width: 20 MHz
+BSS aa:bb:cc:dd:02:ff(on wlan0)
+\tfreq: 2412
+\tsignal: -85.00 dBm
+\tSSID: FarAway
+\tHT operation:
+\t\t * primary channel: 1
+\t\t * secondary channel offset: no secondary
+\t\t * STA channel width: 20 MHz
+BSS aa:bb:cc:dd:03:ff(on wlan0)
+\tfreq: 2452
+\tsignal: -90.00 dBm
+\tSSID: Hidden
+\tHT operation:
+\t\t * primary channel: 9
+\t\t * secondary channel offset: no secondary
+\t\t * STA channel width: 20 MHz
+"""
+
+# Minimal iw scan output for wlan1 (5 GHz AP, ch 36 + 44)
+IW_SCAN_WLAN1 = """\
+BSS 11:22:33:44:01:ff(on wlan1)
+\tfreq: 5180
+\tsignal: -58.00 dBm
+\tSSID: Corp5G
+\tVHT operation:
+\t\t * channel width: 80 MHz
+\t\t * center freq segment 1: 42
+\t\t * center freq segment 2: 0
+BSS 11:22:33:44:02:ff(on wlan1)
+\tfreq: 5220
+\tsignal: -77.00 dBm
+\tSSID: Office5G
+\tVHT operation:
+\t\t * channel width: 80 MHz
+"""
+
+
+class TestGetChannelScan:
+    """Tests for OpenWrtWirelessMixin.get_channel_scan()."""
+
+    def _make_send(self, mode: str = "active"):
+        """Return a _send_command mock routing iw dev / iw scan output."""
+        def _send(cmd, **kw):
+            if cmd.strip().startswith("iw dev") and "scan" not in cmd:
+                return IW_DEV_OUT
+            if "wlan0" in cmd and "scan" in cmd:
+                return IW_SCAN_WLAN0
+            if "wlan1" in cmd and "scan" in cmd:
+                return IW_SCAN_WLAN1
+            return ""
+        return _send
+
+    def test_returns_dict(self, driver):
+        driver._send_command = self._make_send()
+        result = driver.get_channel_scan()
+        assert isinstance(result, dict)
+
+    def test_only_ap_interfaces_included(self, driver):
+        """wlan2 is managed (client) mode — must not appear in results."""
+        driver._send_command = self._make_send()
+        result = driver.get_channel_scan()
+        assert "wlan0" in result
+        assert "wlan1" in result
+        assert "wlan2" not in result
+
+    def test_wlan0_entry_count(self, driver):
+        driver._send_command = self._make_send()
+        result = driver.get_channel_scan()
+        assert len(result["wlan0"]) == 3
+
+    def test_wlan0_entry_required_keys(self, driver):
+        driver._send_command = self._make_send()
+        entry = driver.get_channel_scan()["wlan0"][0]
+        assert set(entry.keys()) >= {
+            "bssid", "ssid", "frequency", "channel", "signal_dbm",
+            "channel_width", "band",
+        }
+
+    def test_wlan0_first_entry_values(self, driver):
+        driver._send_command = self._make_send()
+        entry = driver.get_channel_scan()["wlan0"][0]
+        assert entry["bssid"] == "aa:bb:cc:dd:01:ff"
+        assert entry["ssid"] == "NeighborNet1"
+        assert entry["frequency"] == 2437
+        assert entry["channel"] == 6
+        assert entry["signal_dbm"] == -72
+        assert entry["channel_width"] == 20
+        assert entry["band"] == "2.4GHz"
+
+    def test_wlan0_ch1_entry(self, driver):
+        driver._send_command = self._make_send()
+        entries = driver.get_channel_scan()["wlan0"]
+        ch1 = next(e for e in entries if e["channel"] == 1)
+        assert ch1["signal_dbm"] == -85
+        assert ch1["band"] == "2.4GHz"
+
+    def test_wlan0_hidden_ssid(self, driver):
+        """Empty SSID (hidden) should be stored as empty string."""
+        driver._send_command = self._make_send()
+        entries = driver.get_channel_scan()["wlan0"]
+        ch9 = next(e for e in entries if e["channel"] == 9)
+        assert ch9["ssid"] == "Hidden"
+
+    def test_wlan1_band_is_5ghz(self, driver):
+        driver._send_command = self._make_send()
+        entries = driver.get_channel_scan()["wlan1"]
+        assert all(e["band"] == "5GHz" for e in entries)
+
+    def test_wlan1_80mhz_width(self, driver):
+        driver._send_command = self._make_send()
+        entry = driver.get_channel_scan()["wlan1"][0]
+        assert entry["channel_width"] == 80
+
+    def test_passive_mode_uses_passive_flag(self, driver):
+        """With mode='passive', the scan command must contain 'passive'."""
+        issued_cmds: list[str] = []
+
+        def _send(cmd, **kw):
+            issued_cmds.append(cmd)
+            if cmd.strip().startswith("iw dev") and "scan" not in cmd:
+                return IW_DEV_OUT
+            return ""
+
+        driver._send_command = _send
+        driver.get_channel_scan(mode="passive")
+        scan_cmds = [c for c in issued_cmds if "scan" in c]
+        assert all("passive" in c for c in scan_cmds)
+
+    def test_active_mode_no_passive_flag(self, driver):
+        """With mode='active' (default), scan command must NOT contain 'passive'."""
+        issued_cmds: list[str] = []
+
+        def _send(cmd, **kw):
+            issued_cmds.append(cmd)
+            if cmd.strip().startswith("iw dev") and "scan" not in cmd:
+                return IW_DEV_OUT
+            return ""
+
+        driver._send_command = _send
+        driver.get_channel_scan(mode="active")
+        scan_cmds = [c for c in issued_cmds if "scan" in c]
+        assert all("passive" not in c for c in scan_cmds)
+
+    def test_no_ap_interfaces_returns_empty(self, driver):
+        """If no AP-mode interfaces exist, return empty dict."""
+        no_ap = IW_DEV_OUT.replace("type AP", "type managed")
+        driver._send_command = lambda cmd, **kw: (
+            no_ap if "iw dev" in cmd and "scan" not in cmd else ""
+        )
+        result = driver.get_channel_scan()
+        assert result == {}
+
+    def test_empty_iw_output_returns_empty(self, driver):
+        driver._send_command = lambda cmd, **kw: ""
+        result = driver.get_channel_scan()
+        assert result == {}
+
+    def test_6ghz_band_detected(self, driver):
+        iw_dev_6g = """\
+phy#0
+\tInterface wlan0
+\t\taddr aa:bb:cc:dd:ee:f0
+\t\tssid Net6G
+\t\ttype AP
+"""
+        scan_6g = """\
+BSS aa:bb:cc:dd:01:ff(on wlan0)
+\tfreq: 5975
+\tsignal: -65.00 dBm
+\tSSID: Neighbor6G
+"""
+
+        def _send(cmd, **kw):
+            if "iw dev" in cmd and "scan" not in cmd:
+                return iw_dev_6g
+            if "scan" in cmd:
+                return scan_6g
+            return ""
+
+        driver._send_command = _send
+        entries = driver.get_channel_scan().get("wlan0", [])
+        assert len(entries) == 1
+        assert entries[0]["band"] == "6GHz"
+        assert entries[0]["frequency"] == 5975
+
+
+class TestPushRadioChannel:
+    """Tests for OpenWrtWirelessMixin.push_radio_channel()."""
+
+    def test_issues_uci_set(self, driver):
+        """Must call 'uci set wireless.radio0.channel=11'."""
+        issued: list[str] = []
+        driver._send_command = lambda cmd, **kw: issued.append(cmd) or ""
+        driver.push_radio_channel("radio0", 11)
+        assert any("uci set wireless.radio0.channel=11" in c for c in issued)
+
+    def test_issues_uci_commit(self, driver):
+        issued: list[str] = []
+        driver._send_command = lambda cmd, **kw: issued.append(cmd) or ""
+        driver.push_radio_channel("radio0", 11)
+        assert any("uci commit wireless" in c for c in issued)
+
+    def test_issues_wifi_reload(self, driver):
+        issued: list[str] = []
+        driver._send_command = lambda cmd, **kw: issued.append(cmd) or ""
+        driver.push_radio_channel("radio1", 36)
+        assert any("wifi reload" in c for c in issued)
+
+    def test_auto_channel_zero(self, driver):
+        """channel=0 should set 'auto' in UCI."""
+        issued: list[str] = []
+        driver._send_command = lambda cmd, **kw: issued.append(cmd) or ""
+        driver.push_radio_channel("radio0", 0)
+        assert any("channel=auto" in c or "channel='auto'" in c for c in issued)
+
+    def test_commit_before_reload(self, driver):
+        """UCI commit must happen before wifi reload."""
+        issued: list[str] = []
+        driver._send_command = lambda cmd, **kw: issued.append(cmd) or ""
+        driver.push_radio_channel("radio0", 6)
+        commit_idx = next(i for i, c in enumerate(issued) if "commit" in c)
+        reload_idx = next(i for i, c in enumerate(issued) if "wifi reload" in c)
+        assert commit_idx < reload_idx