feat: build each doc kind with its own MkDocs config and site

tests/cli/test_build_mkdocs.py

@@ -20,10 +20,6 @@ def test_mkdocs_build_full_flow(
         nav_file = cwd / "docforge.nav.yml"
         nav_file.write_text("home: lib/testpkg/index.md\ngroups: {}\n")
 
-        # We need to create a dummy testpkg/index.md for nav resolution if it's there
-        # But generate_sources will create it.
-        # Wait, the current logic runs generate_sources first, THEN generate_config.
-
         result = cli_runner.invoke(
             cli,
             [
@@ -33,16 +29,19 @@ def test_mkdocs_build_full_flow(
                 "testpkg",
                 "--site-name",
                 "Test Site",
-                "--mkdocs-yml",
-                "mkdocs.yml",
             ],
         )
 
         assert result.exit_code == 0
         assert mock_mkdocs_build() is True
-        assert (cwd / "mkdocs.yml").exists()
+
+        config = cwd / "docs" / "mkdocs.lib.yml"
+        assert config.exists()
         assert (cwd / "docs" / "lib" / "testpkg" / "mod.md").exists()
-        assert "docs_dir: docs" in (cwd / "mkdocs.yml").read_text()
+        content = config.read_text(encoding="utf-8")
+        assert "docs_dir: lib" in content
+        assert "site_dir: ../site/lib" in content
+        assert "Home: testpkg/index.md" in content
 
 
 def test_mkdocs_build_missing_module_fails(cli_runner):
@@ -66,7 +65,7 @@ def test_mkdocs_build_without_site_name_uses_module_as_default_full_flow(
         (pkg / "__init__.py").write_text("")
         (pkg / "mod.py").write_text("def f(): ...\n")
 
-        # Create nav spec expected by generate_config
+        # Create nav spec expected by build_lib_nav
         nav_file = cwd / "docforge.nav.yml"
         nav_file.write_text(
             "home: lib/testpkg/index.md\ngroups: {}\n",
@@ -75,25 +74,18 @@ def test_mkdocs_build_without_site_name_uses_module_as_default_full_flow(
 
         result = cli_runner.invoke(
             cli,
-            [
-                "build",
-                "--mkdocs",
-                "--module",
-                "testpkg",
-                "--mkdocs-yml",
-                "mkdocs.yml",
-            ],
+            ["build", "--mkdocs", "--module", "testpkg"],
         )
 
         assert result.exit_code == 0
         assert mock_mkdocs_build() is True
 
-        # MkDocs config must exist
-        mkdocs_yml = cwd / "mkdocs.yml"
-        assert mkdocs_yml.exists()
+        # The per-kind MkDocs config must exist
+        config = cwd / "docs" / "mkdocs.lib.yml"
+        assert config.exists()
 
         # Site name must default to module name
-        content = mkdocs_yml.read_text()
+        content = config.read_text(encoding="utf-8")
         assert "site_name: testpkg" in content
 
         # Docs must be generated under the nested docs/lib dir