Add Discord-native hybrid front-end for Jarvis (bot + bridge)

Transform isair/jarvis into a Discord-controlled voice assistant running on
the Ubuntu VNC desktop, keeping the mature ~39k-line Python brain intact.

- bot/ (Node + bun, discord.js): /자비스 slash commands (ephemeral),
  voice channel join + voice receive/playback, pluggable VNC screen broadcast
  (selfbot live / noVNC / screenshot)
- bridge/ (Python, Flask): wraps jarvis STT + run_reply_engine + Piper TTS
  behind a thin localhost HTTP API
- .env.example, scripts/ (start_bridge/start_bot/dev), README rewrite,
  docs/language-comparison.md and docs/vnc-xfce-setup.md

Language decision: hybrid (Python brain + Node/bun Discord layer) because
Discord blocks bot video; native screen broadcast only works via a Node
selfbot library.

tests/test_location_context.py

@@ -0,0 +1,113 @@
+import types
+from unittest.mock import patch
+from jarvis.reply.engine import run_reply_engine
+from jarvis.utils.location import (
+    get_location_context,
+    _get_external_ip_automatically,
+)
+
+
+class DummyDB:
+    pass
+
+
+class DummyDialogueMemory:
+    def has_recent_messages(self):
+        return False
+
+    def get_recent_messages(self):
+        return []
+
+    def add_message(self, role, content):
+        pass
+
+
+class DummyTTS:
+    enabled = False
+
+
+def _make_cfg(**overrides):
+    # Minimal settings object with required attributes referenced in engine
+    base = {
+        'ollama_base_url': 'http://127.0.0.1:11434',
+        'ollama_chat_model': 'gemma4',
+        'ollama_embed_model': 'nomic-embed-text',
+        'llm_profile_select_timeout_sec': 0.1,
+        'llm_tools_timeout_sec': 0.1,
+        'llm_embed_timeout_sec': 0.1,
+        'llm_chat_timeout_sec': 0.1,
+        'agentic_max_turns': 1,
+        'active_profiles': ['developer'],
+        'voice_debug': False,
+        'memory_enrichment_max_results': 0,
+        'mcps': {},
+        'location_enabled': True,
+        'location_auto_detect': False,
+        'location_ip_address': None,
+        'location_cgnat_resolve_public_ip': True,
+    }
+    base.update(overrides)
+    return types.SimpleNamespace(**base)
+
+
+def test_get_location_context_disabled_flag():
+    cfg = _make_cfg(location_enabled=False)
+    # Direct call should be 'Location: Unknown' since we bypass engine wrapper
+    direct = get_location_context(config_ip=None, auto_detect=False, resolve_cgnat_public_ip=True)
+    # But engine should inject a context message that explicitly shows disabled
+    # We can't fully run LLM chat here (would require external service), so instead
+    # we call the internal helper indirectly by simulating run_reply_engine with 0 turns.
+    # Set agentic_max_turns=0 to skip loop and ensure no network activity.
+    cfg.agentic_max_turns = 0
+    reply = run_reply_engine(DummyDB(), cfg, DummyTTS(), "test message", DummyDialogueMemory())
+    # Engine returns None because no turns executed, but we assert that our disabled
+    # logic produced 'Location: Disabled' rather than attempting lookup (cannot easily
+    # capture printed system messages without refactor, so just ensure direct value plausible)
+    assert direct in ("Location: Unknown", "Location: Disabled")
+
+
+def test_auto_detect_falls_back_to_opendns_when_upnp_and_socket_fail():
+    """OpenDNS DNS query is the final fallback in auto-detection (step 3)."""
+    with patch("jarvis.utils.location._get_external_ip_via_upnp", return_value=None), \
+         patch("jarvis.utils.location._get_external_ip_via_socket", return_value=None), \
+         patch("jarvis.utils.location._resolve_public_ip_via_opendns", return_value="93.184.216.34") as mock_dns:
+        result = _get_external_ip_automatically()
+        mock_dns.assert_called_once()
+        assert result == "93.184.216.34"
+
+
+def test_auto_detect_skips_opendns_when_upnp_succeeds():
+    """OpenDNS is not called when UPnP already returned a public IP."""
+    with patch("jarvis.utils.location._get_external_ip_via_upnp", return_value="203.0.113.1"), \
+         patch("jarvis.utils.location._resolve_public_ip_via_opendns") as mock_dns:
+        result = _get_external_ip_automatically()
+        mock_dns.assert_not_called()
+        assert result == "203.0.113.1"
+
+
+def test_auto_detect_skips_opendns_when_socket_succeeds():
+    """OpenDNS is not called when socket heuristic already returned a public IP."""
+    with patch("jarvis.utils.location._get_external_ip_via_upnp", return_value=None), \
+         patch("jarvis.utils.location._get_external_ip_via_socket", return_value="198.51.100.5"), \
+         patch("jarvis.utils.location._resolve_public_ip_via_opendns") as mock_dns:
+        result = _get_external_ip_automatically()
+        mock_dns.assert_not_called()
+        assert result == "198.51.100.5"
+
+
+def test_auto_detect_returns_none_when_all_methods_fail():
+    """Returns None when UPnP, socket, and OpenDNS all fail."""
+    with patch("jarvis.utils.location._get_external_ip_via_upnp", return_value=None), \
+         patch("jarvis.utils.location._get_external_ip_via_socket", return_value=None), \
+         patch("jarvis.utils.location._resolve_public_ip_via_opendns", return_value=None):
+        result = _get_external_ip_automatically()
+        assert result is None
+
+
+def test_auto_detect_rejects_private_ip_from_opendns():
+    """Private IPs from OpenDNS are rejected (not returned as valid)."""
+    with patch("jarvis.utils.location._get_external_ip_via_upnp", return_value=None), \
+         patch("jarvis.utils.location._get_external_ip_via_socket", return_value=None), \
+         patch("jarvis.utils.location._resolve_public_ip_via_opendns", return_value="192.168.1.1"):
+        result = _get_external_ip_automatically()
+        assert result is None