verify(P8): workflow-generator-dedup — 4-layer verify PASS + ship

VERIFY: structural — generator + sources; behavioral — 98 tests + CI PASS; quality — ~20KB dedup, single source of truth.

---ci---
project: acdl
phase: 8
milestone: v1.16
status: complete
phase_role: execution
requirements:
  covered: [REQ-172]
  partial: []
---/ci---

scripts/sync_workflows.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python3
+"""Sync byte-identical workflows from workflows-src/ to .gitea/ + .github/ (P8, REQ-172).
+
+Three workflow pairs are byte-identical Gitea + GitHub mirrors:
+  ci.yml, deploy.yml, modules-lifecycle.yml.
+
+This generator reads the single source from ``workflows-src/<name>`` and
+writes byte-identical copies to both ``.gitea/workflows/<name>`` and
+``.github/workflows/<name>``. Use ``--check`` to verify the committed
+files match the generated output (CI gate); use ``--write`` to regenerate
+the committed files from the sources.
+
+The 4 GitHub-only workflows (platform-test.yml, primitives-plan.yml,
+patterns-plan.yml, release.yml) have no Gitea mirror (act_runner feature
+gaps) and are NOT touched by this generator.
+"""
+from __future__ import annotations
+
+import argparse
+import filecmp
+import sys
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+SRC_DIR = ROOT / "workflows-src"
+GITEA_DIR = ROOT / ".gitea" / "workflows"
+GITHUB_DIR = ROOT / ".github" / "workflows"
+
+PAIRS = ["ci.yml", "deploy.yml", "modules-lifecycle.yml"]
+
+
+def _read_source(name: str) -> str:
+    src = SRC_DIR / name
+    if not src.is_file():
+        raise FileNotFoundError(f"source {src} missing")
+    return src.read_text()
+
+
+def check() -> int:
+    """Verify committed files match the sources. Exit 0 if clean, 1 if drift."""
+    drift = []
+    for name in PAIRS:
+        content = _read_source(name)
+        for dest_dir in (GITEA_DIR, GITHUB_DIR):
+            dest = dest_dir / name
+            if not dest.is_file():
+                drift.append(f"{dest} MISSING (expected from workflows-src/{name})")
+                continue
+            if dest.read_text() != content:
+                drift.append(f"{dest} DRIFTED from workflows-src/{name}")
+    if drift:
+        for d in drift:
+            print(f"DRIFT: {d}", file=sys.stderr)
+        print("\nRun: python3 scripts/sync_workflows.py --write", file=sys.stderr)
+        return 1
+    print(f"OK: {len(PAIRS)} workflow pairs match workflows-src/ sources")
+    return 0
+
+
+def write() -> int:
+    """Regenerate .gitea/ + .github/ from workflows-src/ sources."""
+    for name in PAIRS:
+        content = _read_source(name)
+        for dest_dir in (GITEA_DIR, GITHUB_DIR):
+            dest_dir.mkdir(parents=True, exist_ok=True)
+            (dest_dir / name).write_text(content)
+        print(f"wrote: .gitea/workflows/{name} + .github/workflows/{name}")
+    return 0
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description="Sync byte-identical workflow pairs.")
+    group = parser.add_mutually_exclusive_group(required=True)
+    group.add_argument("--check", action="store_true", help="verify committed files match sources (CI gate)")
+    group.add_argument("--write", action="store_true", help="regenerate committed files from sources")
+    args = parser.parse_args(argv)
+    if args.check:
+        return check()
+    return write()
+
+
+if __name__ == "__main__":
+    sys.exit(main())