refactor: restructure CLI and improve documentation/typing

- Consolidated CLI commands into [build](cci:1://file:///c:/Users/vishe/WorkSpace/code/aetos/doc-forge/docforge/cli/mkdocs/logic.py:48:0-58:46) and [serve](cci:1://file:///c:/Users/vishe/WorkSpace/code/aetos/doc-forge/docforge/cli/commands.py:70:0-92:32) using `--mkdocs` and `--mcp` flags.
- Separated CLI orchestration logic into [docforge/cli/mkdocs/logic.py](cci:7://file:///c:/Users/vishe/WorkSpace/code/aetos/doc-forge/docforge/cli/mkdocs/logic.py:0:0-0:0) and [docforge/cli/mcp/logic.py](cci:7://file:///c:/Users/vishe/WorkSpace/code/aetos/doc-forge/docforge/cli/mcp/logic.py:0:0-0:0).
- Moved command definitions to [docforge/cli/commands.py](cci:7://file:///c:/Users/vishe/WorkSpace/code/aetos/doc-forge/docforge/cli/commands.py:0:0-0:0), making [main.py](cci:7://file:///c:/Users/vishe/WorkSpace/code/aetos/doc-forge/docforge/cli/main.py:0:0-0:0) a thin entry point.
- Aligned [.pyi](cci:7://file:///c:/Users/vishe/WorkSpace/code/aetos/doc-forge/docforge/cli/main.pyi:0:0-0:0) type stubs with [.py](cci:7://file:///c:/Users/vishe/WorkSpace/code/aetos/doc-forge/tests/conftest.py:0:0-0:0) implementations across the package.
- Added missing docstrings to internal helper functions and core classes.
- Restructured tests into `tests/mkdocs/` and `tests/mcp/`.
- Updated navigation specification to reflect the new project structure.

tests/conftest.py

@@ -1,7 +1,9 @@
 import sys
+import json
+import pytest
 from pathlib import Path
 
-import pytest
+from click.testing import CliRunner
 
 
 @pytest.fixture
@@ -16,3 +18,109 @@ def temp_package(tmp_path: Path):
     sys.path.insert(0, str(tmp_path))
     yield pkg
     sys.path.remove(str(tmp_path))
+
+
+@pytest.fixture
+def cli_runner() -> CliRunner:
+    """Click CLI runner."""
+    return CliRunner()
+
+
+@pytest.fixture
+def fake_mkdocs_yml(tmp_path: Path) -> Path:
+    """Create a minimal mkdocs.yml file."""
+    yml = tmp_path / "mkdocs.yml"
+    yml.write_text(
+        """
+site_name: Test Docs
+nav: []
+plugins:
+  - mkdocstrings
+""",
+        encoding="utf-8",
+    )
+    return yml
+
+
+@pytest.fixture
+def mock_mkdocs_load_config(monkeypatch):
+    """Mock mkdocs.config.load_config."""
+    def fake_load_config(path):
+        return object()  # dummy config object
+
+    monkeypatch.setattr(
+        "mkdocs.config.load_config",
+        fake_load_config,
+    )
+
+
+@pytest.fixture
+def mock_mkdocs_build(monkeypatch):
+    called = {"value": False}
+
+    def fake_build(config):
+        called["value"] = True
+
+    monkeypatch.setattr(
+        "mkdocs.commands.build.build",
+        fake_build,
+    )
+    return lambda: called["value"]
+
+
+@pytest.fixture
+def mock_mkdocs_serve(monkeypatch):
+    called = {"value": False}
+
+    def fake_serve(*args, **kwargs):
+        called["value"] = True
+
+    monkeypatch.setattr(
+        "mkdocs.commands.serve.serve",
+        fake_serve,
+    )
+    return lambda: called["value"]
+
+@pytest.fixture
+def fake_mcp_docs(tmp_path: Path) -> Path:
+    """
+    Create a minimal valid MCP bundle in mcp_docs/.
+    """
+    mcp_root = tmp_path / "mcp_docs"
+    modules_dir = mcp_root / "modules"
+    modules_dir.mkdir(parents=True)
+
+    (mcp_root / "index.json").write_text(
+        json.dumps({"project": "test", "type": "docforge-model"}),
+        encoding="utf-8",
+    )
+
+    (mcp_root / "nav.json").write_text(
+        json.dumps([]),
+        encoding="utf-8",
+    )
+
+    (modules_dir / "test.mod.json").write_text(
+        json.dumps({"module": "test.mod", "content": {}}),
+        encoding="utf-8",
+    )
+
+    return mcp_root
+
+
+@pytest.fixture
+def mock_mcp_server_run(monkeypatch):
+    """
+    Mock MCPServer.run so no real server is started.
+    """
+    called = {"value": False}
+
+    def fake_run(self, transport="streamable-http"):
+        called["value"] = True
+
+    monkeypatch.setattr(
+        "docforge.servers.MCPServer.run",
+        fake_run,
+    )
+
+    return lambda: called["value"]