fix(callkit): add voip background mode + mic permission so incoming calls work

Incoming voice calls were unusable: the CallKit screen flashed the caller's
name, auto-dismissed, reappeared as 'Unknown', and couldn't be answered.

Root cause: the app's UIBackgroundModes was missing 'voip', so callservicesd
DENIED creation of the CallKit call source and reset the provider
(providerDidReset → CallManager.handleCallKitReset → currentCallUUID=nil +
callState=.ended). Found via the simulator's com.apple.calls.callkit unified
log ('Denying creation of CXXPCCallSource … Not accepting connection'); the
device diag.log only showed the effect (providerDidReset).

- Info.plist: add 'voip' (+ 'audio') to UIBackgroundModes; add
  NSMicrophoneUsageDescription (the 'no audio' half — mic capture needs it).
  'voip' is just an Info.plist key, no provisioning capability required.
- Tests/interop/voice_caller.py: headless LXST caller (Sideband's
  ReticulumTelephone, wire-identical) that dials the sim's telephony dest to
  reproduce the incoming-call/CallKit path on the simulator — where CallKit
  runs, so the bug + the framework deny reason are observable (unlike on device).

Verified on sim: with the fix, reportIncomingCall succeeds + callservicesd
'Created CXXPCCallSource' — no deny, no providerDidReset.

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

Author: torlando-agent[bot]

Sources/ColumbaApp/Resources/Info.plist

@@ -29,6 +29,8 @@
 	<string>Columba shares your location with contacts you explicitly choose, so they can see where you are during an active sharing session.</string>
 	<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
 	<string>Columba keeps sharing your location with the contacts you chose even when the app is in the background, so a sharing session you started doesn't silently stop. You can stop sharing at any time from the conversation or from Settings.</string>
+	<key>NSMicrophoneUsageDescription</key>
+	<string>Columba uses the microphone for encrypted voice calls over the mesh network.</string>
 	<key>UIAppFonts</key>
 	<array>
 		<string>materialdesignicons.ttf</string>
@@ -42,9 +44,11 @@
 	</dict>
 	<key>UIBackgroundModes</key>
 	<array>
+		<string>audio</string>
 		<string>bluetooth-central</string>
 		<string>bluetooth-peripheral</string>
 		<string>location</string>
+		<string>voip</string>
 	</array>
 	<key>UILaunchScreen</key>
 	<dict/>

Tests/interop/voice_caller.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+"""Headless LXST voice caller — dials the iOS Columba sim's telephony
+destination so its incoming-call / CallKit path fires, for debugging the
+"call screen dismisses + reappears as Unknown" bug on the sim (full log access).
+
+Uses Sideband's own ReticulumTelephone (which wraps LXST.Telephone), so it's
+wire-identical to a Sideband user placing the call. Joins the host's shared
+RNS instance (lxmd) exactly like the interop peer, so it shares Columba's
+transport.
+
+Usage:
+  PYTHONPATH unneeded — paths injected below.
+  python3 voice_caller.py <columba_identity_hex> [ring_seconds]
+"""
+import sys, os, time, threading
+
+sys.path.insert(0, os.path.expanduser("~/repos/LXST"))
+sys.path.insert(0, os.path.expanduser("~/repos/Sideband"))
+
+import RNS  # noqa: E402
+from sbapp.sideband.voice import ReticulumTelephone  # noqa: E402
+
+COLUMBA_ID_HEX = sys.argv[1] if len(sys.argv) > 1 else "695f23533fe3547183f1b550d8552ae8"
+RING_SECONDS = int(sys.argv[2]) if len(sys.argv) > 2 else 25
+
+
+def main():
+    RNS.Reticulum()  # connect to the shared lxmd instance (share_instance=Yes)
+    identity = RNS.Identity()
+    print(f"[caller] my identity={RNS.prettyhexrep(identity.hash)}", flush=True)
+
+    phone = ReticulumTelephone(identity, owner=None)
+    # NB: don't call phone.start() — its run() loop is Sideband hw-state polling
+    # and isn't present on this build; the wrapped LXST.Telephone drives the
+    # call protocol itself. We just need to keep the process alive.
+    time.sleep(1.0)
+
+    phone.announce()  # so Columba can resolve/path us (matches the 'correct name' case)
+    print("[caller] announced own telephony", flush=True)
+
+    id_bytes = bytes.fromhex(COLUMBA_ID_HEX)
+    tel_dest = RNS.Destination.hash_from_name_and_identity("lxst.telephony", id_bytes)
+    print(f"[caller] Columba telephony dest = {tel_dest.hex()}", flush=True)
+
+    if not RNS.Transport.has_path(tel_dest):
+        RNS.Transport.request_path(tel_dest)
+        deadline = time.time() + 30
+        while not RNS.Transport.has_path(tel_dest) and time.time() < deadline:
+            time.sleep(0.5)
+    if not RNS.Transport.has_path(tel_dest):
+        print("[caller] NO PATH to Columba telephony after 30s — is the sim "
+              "announcing lxst.telephony + bridged through lxmd? aborting.", flush=True)
+        return 1
+    print(f"[caller] path to telephony resolved ({RNS.Transport.hops_to(tel_dest)} hops); DIALING", flush=True)
+
+    result = phone.dial(id_bytes)
+    print(f"[caller] dial() -> {result}", flush=True)
+
+    # state: 0=AVAILABLE 1=CONNECTING 2=RINGING 3=IN_CALL (is_* are @property, no parens)
+    _names = {0: "AVAILABLE", 1: "CONNECTING", 2: "RINGING", 3: "IN_CALL"}
+    for i in range(RING_SECONDS):
+        st = phone.state
+        print(f"[caller] t={i:>2}s state={st}({_names.get(st, '?')})", flush=True)
+        time.sleep(1.0)
+
+    print("[caller] hanging up", flush=True)
+    try:
+        phone.hangup()
+    except Exception as e:
+        print(f"[caller] hangup error: {e}", flush=True)
+    time.sleep(2.0)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())