feat(mcp): scaffold three project context tools

mcp_servers/project_context/registry.py

@@ -0,0 +1,23 @@
+"""Immutable registry composed before member work starts to prevent merge conflicts."""
+
+from __future__ import annotations
+
+from types import MappingProxyType
+from typing import Any
+
+from .foundation import ToolTemplate
+from .tools.change_context import TOOL as CHANGE_CONTEXT_TOOL
+from .tools.issue_context import TOOL as ISSUE_CONTEXT_TOOL
+from .tools.knowledge_search import TOOL as KNOWLEDGE_SEARCH_TOOL
+
+TOOLS: tuple[ToolTemplate, ...] = (
+    ISSUE_CONTEXT_TOOL,
+    KNOWLEDGE_SEARCH_TOOL,
+    CHANGE_CONTEXT_TOOL,
+)
+TOOLS_BY_NAME = MappingProxyType({tool.name: tool for tool in TOOLS})
+TOOL_NAMES = tuple(tool.name for tool in TOOLS)
+
+
+def tool_declarations() -> list[dict[str, Any]]:
+    return [tool.declaration() for tool in TOOLS]