feat(rawcli): LF T5577 identify + clear stale result per identify

- identify clears the previous field/protocol/transponder up front, so
  consecutive identifies (esp. when swapping tags) never show stale data.
- LF identify: probe a T5577 by reading config block 0 (lf.t55.readbl(0)).
  A valid config confirms the T5577 and, decoded via T5577Config, names
  what it's emulating — "T5577 (EM4100 / EM4102)", "T5577 (HID Prox)", etc.
  (exact-word map, else modulation family). Tightly gated (status ok,
  non-trivial config, known modulation, sane max_block) so no-tag reads
  don't false-positive; lf.search() couldn't do this without demod.
- format_summary shows the config word for LF (no UID).

4 tests (T5577 emulation report, no-T5577, stale-clear).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

pm3py/cli/rawcli/identify.py

@@ -141,6 +141,10 @@ def identify(session, emit=None) -> dict:
     each annotated trace line (default: no trace). Returns a summary dict."""
     emit = emit or (lambda _line: None)
     dev = session.device
+    # clear the previous result up front — a new identify must never show stale field/transponder
+    session.field = None
+    session.transponder = None
+    session.protocol = "hf14a"
     if dev is None:
         return {"found": False, "error": "no device connected"}
 
@@ -174,11 +178,67 @@ def identify(session, emit=None) -> dict:
         return {"found": True, "field": "hf", "protocol": "15693",
                 "transponder": "ISO15693", "uid": uid15}
 
-    # LF: lf.search() only captures samples — it can't confirm a tag without demod, so it would
-    # always false-positive. Reliable LF identify (T55xx probe / EM4100 demod) is a follow-up.
+    # LF: probe for a T5577 by reading its config block (block 0). A valid config word confirms
+    # a T5577 and — decoded — tells us what it's emulating. lf.search() can't do this (no demod).
+    lf = _identify_lf(dev, session, emit)
+    if lf:
+        return lf
+
     return {"found": False}
 
 
+# Known T5577 config words → the tag it's set up to emulate (Proxmark3 config-block table).
+_T5577_EMULATION = {
+    0x00148040: "EM4100 / EM4102",
+    0x00107060: "HID Prox",
+    0x00081040: "Indala",
+    0x903F0082: "FDX-B",
+    0x00088040: "Viking",
+    0x000880E8: "raw / default",
+}
+
+
+def _infer_emulation(cfg) -> str:
+    """From a decoded T5577 config, name the emulated tag (exact word, else modulation family)."""
+    exact = _T5577_EMULATION.get(int(cfg))
+    if exact:
+        return exact
+    mod = cfg.modulation
+    if not isinstance(mod, str):
+        return "unknown"
+    family = ("EM/ASK" if mod == "ASK" else "HID/AWID" if mod.startswith("FSK")
+              else "Indala/PSK" if mod.startswith("PSK") else "FDX-B/Nedap" if "biphase" in mod
+              else mod)
+    return f"{family} · {mod} RF/{cfg.data_bit_rate}"
+
+
+def _identify_lf(dev, session, emit):
+    """Read T55xx block 0; if it decodes to a plausible config, report the T5577 and what it
+    emulates. Tightly gated so no-tag reads don't false-positive."""
+    r = _try(lambda: dev.lf.t55.readbl(0), None)
+    if not isinstance(r, dict) or r.get("status") != 0:
+        return None
+    raw = r.get("raw") or b""
+    if len(raw) < 4:
+        return None
+    config = int.from_bytes(raw[:4], "big")
+    if config in (0, 0xFFFFFFFF):
+        return None
+    try:
+        from pm3py.sim import T5577Config
+        cfg = T5577Config(config)
+    except Exception:
+        return None
+    if not isinstance(cfg.modulation, str) or not (1 <= cfg.max_block <= 8):
+        return None                                    # implausible → probably no T5577
+    emit(f"  T55xx block 0 = 0x{config:08X}  "
+         f"({cfg.modulation}, RF/{cfg.data_bit_rate}, {cfg.max_block} blocks)")
+    session.field, session.protocol = "lf", "lf"
+    session.transponder = f"T5577 ({_infer_emulation(cfg)})"
+    return {"found": True, "field": "lf", "protocol": "lf",
+            "transponder": session.transponder, "config": f"{config:08X}"}
+
+
 def _probe_version(dev, fmt, emit) -> tuple[str | None, bytes | None]:
     """Send a real GET_VERSION (0x60 +CRC), trace the exchange, decode the exact model."""
     cmd = b"\x60"
@@ -208,6 +268,12 @@ def clear(session) -> None:
 def format_summary(result: dict) -> str:
     if not result.get("found"):
         return f"no tag found{': ' + result['error'] if result.get('error') else ''}"
-    uid = result.get("uid")
-    uid_hex = uid.hex().upper() if isinstance(uid, (bytes, bytearray)) else (uid or "?")
-    return f"{result['transponder']}  ({result['field'].upper()} / {result['protocol']})  UID {uid_hex}"
+    if result.get("uid"):
+        uid = result["uid"]
+        detail = f"UID {uid.hex().upper() if isinstance(uid, (bytes, bytearray)) else uid}"
+    elif result.get("config"):
+        detail = f"config 0x{result['config']}"
+    else:
+        detail = ""
+    head = f"{result['transponder']}  ({result['field'].upper()} / {result['protocol']})"
+    return f"{head}  {detail}".rstrip()

tests/test_rawcli.py

@@ -182,6 +182,7 @@ def _mock_device(scan14=None, scan15=None, version=None):
     dev.hf.iso14a.scan.return_value = scan14 or {"found": False}
     dev.hf.iso15.scan.return_value = scan15 or {"found": False}
     dev.lf.search.return_value = None
+    dev.lf.t55.readbl.return_value = {"status": 1, "raw": b""}   # no T55xx by default
     dev.hf.iso14a.raw.return_value = {"raw": (version + b"\x99\x88") if version else None}
     return dev
 
@@ -228,6 +229,32 @@ class TestIdentify:
         s = RawSession(device=dev)
         assert identify(s)["found"] is False and s.transponder is None
 
+    def test_lf_t5577_reports_emulation(self):
+        # T55xx block 0 = EM4100 config -> "T5577 (EM4100 / EM4102)"
+        dev = _mock_device()
+        dev.lf.t55.readbl.return_value = {"status": 0, "raw": bytes.fromhex("00148040")}
+        s = RawSession(device=dev)
+        r = identify(s)
+        assert r["found"] and s.field == "lf" and s.protocol == "lf"
+        assert s.transponder == "T5577 (EM4100 / EM4102)"
+        assert r["config"] == "00148040"
+
+    def test_lf_no_t5577_not_found(self):
+        dev = _mock_device()
+        dev.lf.t55.readbl.return_value = {"status": 1, "raw": b""}   # no T55xx response
+        assert identify(RawSession(device=dev))["found"] is False
+
+    def test_identify_clears_stale_result(self):
+        # a second identify that finds nothing must clear the previous tag from the session
+        dev = _mock_device(scan14={"found": True, "sak": 0x08, "atqa": "0400", "uid": "b978423d"})
+        s = RawSession(device=dev)
+        identify(s)
+        assert s.transponder == "MIFARE Classic 1K"
+        dev.hf.iso14a.scan.return_value = {"found": False}          # tag removed
+        dev.lf.t55.readbl.return_value = {"status": 1, "raw": b""}
+        identify(s)
+        assert s.transponder is None and s.field is None            # no stale data
+
     def test_sak_names_from_an10833(self):
         assert name_14a({"sak": 0x18}) == "MIFARE Classic 4K"
         assert name_14a({"sak": 0x20}).startswith("ISO14443-4")