feat: WP-0001 + WP-0002 complete — LEVEL1 core + service interfaces

WP-0001 (Foundation & LEVEL1 Core):
- manifest model (FR-100), MD→DOCX builder (FR-200), DOCX→MD importer
  (FR-300/400), template family registry (FR-600), drift detector (FR-700),
  CLI wiring, pre-commit config, CI skeleton, regression harness

WP-0002 (Service Interfaces & Workflow Orchestration):
- REST service via FastAPI (FR-900): /health, /version, /capabilities,
  /templates, /styles, /validate, /build, /import, /compare,
  /templates/register, /workflows/{name}, /evidence/{run_id}
- Evidence & report store (FR-1400): JSON-backed, per-run, retrievable
  through all interfaces, classification (pass/warnings/failed)
- Composite workflow orchestration (FR-1300): single-file-roundtrip,
  multi-file-roundtrip, release-regression, family-switch-build
- MCP server via FastMCP (FR-1000): all tools + resources
- CLI additions: `markidocx serve`, `markidocx workflow`, `markidocx mcp`
- Interface parity tests: CLI / REST / MCP produce equivalent results

135 tests passing, ruff + mypy clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/regression/test_roundtrip.py

@@ -0,0 +1,151 @@
+"""End-to-end round-trip regression tests (FR-1100).
+
+Tests the full build → import → compare cycle using the SIMPLE_MARKDOWN
+fixture and per-family smoke tests.
+"""
+
+from __future__ import annotations
+
+import textwrap
+from pathlib import Path
+
+import yaml
+
+from markidocx.builder import build_document
+from markidocx.differ import compare
+from markidocx.importer import import_document
+from markidocx.manifest import load_manifest
+
+LEVEL1_MARKDOWN = textwrap.dedent("""\
+    # Document Title
+
+    This is the introduction paragraph.
+
+    ## Section One
+
+    - Item alpha
+    - Item beta
+    - Item gamma
+
+    ## Section Two
+
+    | Column A | Column B |
+    |----------|----------|
+    | row1a    | row1b    |
+    | row2a    | row2b    |
+
+    1. First ordered item
+    2. Second ordered item
+""")
+
+
+def _make_project(tmp_path: Path, family: str, content: str) -> Path:
+    """Create a minimal project directory and return the manifest path."""
+    (tmp_path / "doc.md").write_text(content, encoding="utf-8")
+    manifest_path = tmp_path / "manifest.yaml"
+    manifest_path.write_text(
+        yaml.dump(
+            {
+                "project": {"name": f"test-{family}", "feature_level": "level1", "family": family},
+                "sources": [{"path": "doc.md"}],
+                "output": {"dir": "./dist"},
+            }
+        )
+    )
+    (tmp_path / "dist").mkdir()
+    return manifest_path
+
+
+class TestRoundtripArticle:
+    def test_build_import_cycle(self, tmp_path: Path) -> None:
+        manifest_path = _make_project(tmp_path, "article", LEVEL1_MARKDOWN)
+        manifest = load_manifest(manifest_path)
+
+        build_result = build_document(manifest)
+        assert build_result.success, f"Build failed: {build_result.errors}"
+
+        import_result = import_document(manifest, build_result.output_path)
+        assert import_result.success, f"Import failed: {import_result.warnings}"
+        assert import_result.mapping_status == "redistributed"
+
+    def test_heading_structure_preserved(self, tmp_path: Path) -> None:
+        manifest_path = _make_project(tmp_path, "article", LEVEL1_MARKDOWN)
+        manifest = load_manifest(manifest_path)
+        build_result = build_document(manifest)
+        import_result = import_document(manifest, build_result.output_path)
+        assert import_result.success
+
+        md = import_result.output_files[0].read_text(encoding="utf-8")
+        report = compare(LEVEL1_MARKDOWN, md)
+        broken_headings = [b for b in report.broken if b.startswith("heading:")]
+        assert not broken_headings, f"Headings lost in round-trip: {broken_headings}"
+
+    def test_no_errors_on_clean_roundtrip(self, tmp_path: Path) -> None:
+        manifest_path = _make_project(tmp_path, "article", LEVEL1_MARKDOWN)
+        manifest = load_manifest(manifest_path)
+        build_result = build_document(manifest)
+        assert not build_result.errors
+
+
+class TestRoundtripBook:
+    def test_build_import_cycle(self, tmp_path: Path) -> None:
+        manifest_path = _make_project(tmp_path, "book", LEVEL1_MARKDOWN)
+        manifest = load_manifest(manifest_path)
+        build_result = build_document(manifest)
+        assert build_result.success
+
+        import_result = import_document(manifest, build_result.output_path)
+        assert import_result.success
+
+
+class TestRoundtripWebsite:
+    def test_build_import_cycle(self, tmp_path: Path) -> None:
+        manifest_path = _make_project(tmp_path, "website", LEVEL1_MARKDOWN)
+        manifest = load_manifest(manifest_path)
+        build_result = build_document(manifest)
+        assert build_result.success
+
+        import_result = import_document(manifest, build_result.output_path)
+        assert import_result.success
+
+
+class TestMultiFileRoundtrip:
+    def test_two_source_files(self, tmp_path: Path) -> None:
+        ch1 = textwrap.dedent("""\
+            # Chapter One
+
+            Introduction text.
+
+            - Point one
+            - Point two
+        """)
+        ch2 = textwrap.dedent("""\
+            # Chapter Two
+
+            Conclusion text.
+
+            ## Subsection
+
+            Final paragraph.
+        """)
+        (tmp_path / "ch1.md").write_text(ch1, encoding="utf-8")
+        (tmp_path / "ch2.md").write_text(ch2, encoding="utf-8")
+        manifest_path = tmp_path / "manifest.yaml"
+        manifest_path.write_text(
+            yaml.dump(
+                {
+                    "project": {"name": "two-chap", "feature_level": "level1", "family": "book"},
+                    "sources": [{"path": "ch1.md"}, {"path": "ch2.md"}],
+                    "output": {"dir": "./dist"},
+                }
+            )
+        )
+        (tmp_path / "dist").mkdir()
+        manifest = load_manifest(manifest_path)
+        build_result = build_document(manifest)
+        assert build_result.success
+
+        import_result = import_document(manifest, build_result.output_path)
+        assert import_result.success
+        # Should have 2 output files (redistributed) or 1 merged
+        assert len(import_result.output_files) >= 1