server+ui: detect card removal passively and reflect it within 2s

The UI only noticed a removed card when some user action ran a real card
command (e.g. Check status); /api/status is a cached-state read that kept
returning the old card, and _handle_card_disconnect() did not clear
app.card/rs.

- start_card_monitor() registers a pyscard CardObserver for our reader;
  it only polls SCardGetStatusChange (no APDU, no connection, no extra
  process), and on removal sets server.card_present=False and calls
  _handle_card_disconnect() under _CARD_LOCK
- /api/status now exposes connected (session usable) and card_present
  (physically inserted) and masks card/profile/atr/selection when not
  connected; _CARD_CONNECTED is initialized from card presence instead of
  being unconditionally True
- the 2s UI poll includes /api/status; on disconnect it switches to the
  existing 'No card detected. Insert card and click Equip' state, or the
  new 'Card inserted — press Equip' hint when the card is back; the old
  _hadData heuristic is gone

Tests for the observer (filtering, removal, insertion) and the UI state
transitions. SW cache v90 -> v91.

pysim_otaman_server/__main__.py

@@ -12,7 +12,7 @@ from pySim.cards import UiccCardBase
 
 from .shell import load_pysim_app
 from . import fastinit
-from .server import PysimHandler, StderrApduTracer, _LoggingApduTracer, VERSION, _send_terminal_profile, _DefaultProactiveHandler, _handle_proactive_chain, _send_status, _init_proactive_session, _timing_on, _tlog, _set_menu_timeout
+from .server import PysimHandler, StderrApduTracer, _LoggingApduTracer, VERSION, _send_terminal_profile, _DefaultProactiveHandler, _handle_proactive_chain, _send_status, _init_proactive_session, _timing_on, _tlog, _set_menu_timeout, start_card_monitor
 
 
 _server_start = 0
@@ -93,6 +93,8 @@ def main():
         t_phase = time.time()
         sl = mod.init_reader(opts, **kwargs)
         _tlog('init_reader: %.0fms' % ((time.time() - t_phase) * 1000))
+        if getattr(sl, '_reader', None) is not None:
+            start_card_monitor(str(sl._reader))
         scc = SimCardCommands(sl)
         scc.cat_cla = '80'  # UICC CLA default; overridden for SIM after init_card
         scc._tp.proactive_handler = _DefaultProactiveHandler()
@@ -179,10 +181,11 @@ def main():
     server.event_list = event_list
     server.menu_active = False
     server.stk_pending = None
-    # Set server reference for polling timer and mark card as connected
+    server.card_present = card is not None
+    # Set server reference for polling timer and mark the card session state
     import pysim_otaman_server.server
     pysim_otaman_server.server._server_ref = server
-    pysim_otaman_server.server._CARD_CONNECTED = True
+    pysim_otaman_server.server._CARD_CONNECTED = card is not None
     if opts.poll_interval is not None:
         pysim_otaman_server.server._set_poll_interval(opts.poll_interval)
     # Auto-enable polling if card initialized successfully (unless interval is 0)

pysim_otaman_server/server.py

@@ -11,6 +11,7 @@ from http.server import HTTPServer, BaseHTTPRequestHandler
 from io import StringIO
 from pySim.transport import ApduTracer, ProactiveHandler
 from pySim.cards import UiccCardBase
+from smartcard.CardMonitoring import CardMonitor, CardObserver
 
 import gsm0338  # registers 'gsm03.38' codec
 from construct import GreedyBytes
@@ -1034,6 +1035,48 @@ def _handle_card_disconnect():
     _reset_proactive_log()
 
 
+class _CardPresenceObserver(CardObserver):
+    """Passive PC/SC presence watcher: pyscard's CardMonitor only polls
+    SCardGetStatusChange (no connection, no APDUs), so it can never interleave
+    with our APDU traffic. We only update flags and tear down card state."""
+
+    def __init__(self, reader_name):
+        self.reader_name = reader_name
+
+    def update(self, observable, handlers):
+        addedcards, removedcards = handlers
+        try:
+            for card in removedcards:
+                if str(getattr(card, 'reader', '')) == self.reader_name:
+                    sys.stderr.write('CARD-WATCH: card removed from %s\n' % self.reader_name)
+                    with _CARD_LOCK:
+                        if _server_ref:
+                            _server_ref.card_present = False
+                        _handle_card_disconnect()
+            for card in addedcards:
+                if str(getattr(card, 'reader', '')) == self.reader_name:
+                    sys.stderr.write('CARD-WATCH: card inserted into %s (press Equip)\n' % self.reader_name)
+                    with _CARD_LOCK:
+                        if _server_ref:
+                            _server_ref.card_present = True
+        except Exception as e:
+            sys.stderr.write('CARD-WATCH error: %s\n' % e)
+
+
+_card_presence_observer = None
+
+def start_card_monitor(reader_name):
+    """Start the process-wide pyscard monitor (one daemon thread, no process)
+    and register our reader's presence observer."""
+    global _card_presence_observer
+    if not reader_name:
+        return None
+    if _card_presence_observer is None:
+        _card_presence_observer = _CardPresenceObserver(reader_name)
+        CardMonitor().addObserver(_card_presence_observer)
+    return _card_presence_observer
+
+
 def _init_proactive_session():
     global _PROACTIVE_SESSION_START
     _PROACTIVE_SESSION_START = time.time()
@@ -1526,9 +1569,19 @@ class PysimHandler(BaseHTTPRequestHandler):
             lchan = rs.lchan[0] if rs else None
             cur_file = lchan.selected_file if lchan else None
             scc = app.card._scc if app and app.card else None
+            card = app.card if app else None
+            connected = bool(_CARD_CONNECTED and card is not None)
+            if not connected:
+                rs = None
+                lchan = None
+                cur_file = None
+                scc = None
+                card = None
             data = {
                 'reader': str(self.server.sl) if self.server.sl else None,
-                'card': app.card.name if app and app.card else None,
+                'connected': connected,
+                'card_present': bool(getattr(self.server, 'card_present', False)),
+                'card': card.name if card else None,
                 'profile': str(rs.profile) if rs and rs.profile else None,
                 'app_ready': app is not None,
                 'adm_verified': rs.adm_verified if rs else False,
@@ -1672,6 +1725,7 @@ class PysimHandler(BaseHTTPRequestHandler):
                 self.server.scc = self.server.app.card._scc
                 self.server.scc.cat_cla = '80' if isinstance(self.server.card, UiccCardBase) else 'a0'
                 _CARD_CONNECTED = True
+                self.server.card_present = True
                 _poll_enable()
                 sm, el = _send_terminal_profile(self.server.scc, self.server.terminal_profile)
                 self.server.sim_menu = sm