fix: prune dead web_search tool — ddgs never installed (#87)

Remove DuckDuckGoTools import, all web_search registrations across 4 toolkit
factories, catalog entry, safety classification, prompt references, and
session regex. Total: -41 lines of dead code.

consult_grok is functional (grok_enabled=True, API key set) and opt-in,
so it stays — but Timmy never calls it autonomously, which is correct
sovereign behavior (no cloud calls unless user permits).

Closes #87

tests/timmy/test_timmy_tools.py

@@ -29,7 +29,7 @@ def clear_usage():
 
 class TestToolTracking:
     def test_track_creates_agent_entry(self):
-        _track_tool_usage("agent-1", "web_search", success=True)
+        _track_tool_usage("agent-1", "calculator", success=True)
         assert "agent-1" in _TOOL_USAGE
         assert len(_TOOL_USAGE["agent-1"]) == 1
 
@@ -132,7 +132,6 @@ class TestToolCatalog:
     def test_catalog_contains_base_tools(self):
         catalog = get_all_available_tools()
         base_tools = {
-            "web_search",
             "shell",
             "python",
             "read_file",
@@ -141,6 +140,8 @@ class TestToolCatalog:
         }
         for tool_id in base_tools:
             assert tool_id in catalog, f"Missing base tool: {tool_id}"
+        # web_search removed — dead code, ddgs never installed (#87)
+        assert "web_search" not in catalog
 
     def test_catalog_tool_structure(self):
         catalog = get_all_available_tools()
@@ -153,7 +154,6 @@ class TestToolCatalog:
     def test_catalog_orchestrator_has_all_base_tools(self):
         catalog = get_all_available_tools()
         base_tools = {
-            "web_search",
             "shell",
             "python",
             "read_file",
@@ -167,7 +167,6 @@ class TestToolCatalog:
 
     def test_catalog_echo_research_tools(self):
         catalog = get_all_available_tools()
-        assert "echo" in catalog["web_search"]["available_in"]
         assert "echo" in catalog["read_file"]["available_in"]
         # Echo should NOT have shell
         assert "echo" not in catalog["shell"]["available_in"]