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_tool_search_tool.py

@@ -0,0 +1,69 @@
+"""Unit tests for the toolSearchTool builtin."""
+
+from unittest.mock import patch
+
+import pytest
+
+from jarvis.tools.builtin.tool_search import ToolSearchTool
+from jarvis.tools.base import ToolContext
+
+
+def _ctx(cfg):
+    return ToolContext(
+        db=None,
+        cfg=cfg,
+        system_prompt="",
+        original_prompt="",
+        redacted_text="",
+        max_retries=0,
+        user_print=lambda _m: None,
+        language=None,
+    )
+
+
+class TestToolSearchTool:
+    def test_rejects_missing_query(self, mock_config):
+        tool = ToolSearchTool()
+        result = tool.run({}, _ctx(mock_config))
+        assert result.success is False
+        assert "query" in (result.error_message or "").lower()
+
+    def test_invokes_select_tools_and_formats_list(self, mock_config):
+        tool = ToolSearchTool()
+        with patch(
+            "jarvis.tools.builtin.tool_search.select_tools",
+            return_value=["webSearch", "stop", "toolSearchTool", "getWeather"],
+        ) as mock_sel:
+            result = tool.run({"query": "look up a fact"}, _ctx(mock_config))
+        assert mock_sel.called
+        assert result.success is True
+        text = result.reply_text or ""
+        # Sentinel and self are filtered out; real tools appear as
+        # `name: description`.
+        assert "webSearch" in text
+        assert "getWeather" in text
+        assert "stop" not in text.split("\n")[0]
+        assert "toolSearchTool" not in text.splitlines()[0]
+        # Each line has the colon-joined description format.
+        for line in text.splitlines():
+            assert ":" in line or line.strip() in ("webSearch", "getWeather")
+
+    def test_empty_result_returns_honest_note(self, mock_config):
+        tool = ToolSearchTool()
+        with patch(
+            "jarvis.tools.builtin.tool_search.select_tools",
+            return_value=["stop", "toolSearchTool"],
+        ):
+            result = tool.run({"query": "do something"}, _ctx(mock_config))
+        assert result.success is True
+        assert "no additional tools" in (result.reply_text or "").lower()
+
+    def test_select_tools_exception_returns_error(self, mock_config):
+        tool = ToolSearchTool()
+        with patch(
+            "jarvis.tools.builtin.tool_search.select_tools",
+            side_effect=RuntimeError("router down"),
+        ):
+            result = tool.run({"query": "x"}, _ctx(mock_config))
+        assert result.success is False
+        assert "router down" in (result.error_message or "")