Add discovery reconciliation engine

railiance_fabric/cli.py

@@ -14,6 +14,7 @@ from .loader import declaration_files, load_yaml
 from .graph import FabricGraph, build_graph
 from .graph_explorer import fabric_graph_explorer_payload
 from .llm_extraction import LLMExtractionConfig
+from .reconciliation import reconcile_discovery_snapshots
 from .scanner import ScanOptions, scan_repo
 from .validation import validate_roots
 
@@ -73,6 +74,7 @@ def build_parser() -> argparse.ArgumentParser:
     scan.add_argument("--profile", default="deterministic")
     scan.add_argument("--dry-run", action="store_true", help="Do not write anywhere except an explicit --output file.")
     scan.add_argument("--output", type=Path, default=None, help="Write the discovery snapshot JSON to a file.")
+    scan.add_argument("--previous-snapshot", type=Path, default=None, help="Reconcile against a previous discovery snapshot JSON.")
     scan.add_argument("--json", action="store_true", help="Print the discovery snapshot JSON to stdout.")
     scan.add_argument("--llm", action="store_true", help="Enable llm-connect assisted extraction.")
     scan.add_argument("--llm-provider", default="mock", help="llm-connect provider name.")
@@ -410,6 +412,16 @@ def _scan_repo(args: argparse.Namespace) -> int:
             ),
         )
     )
+    if args.previous_snapshot:
+        try:
+            previous = json.loads(args.previous_snapshot.read_text(encoding="utf-8"))
+        except Exception as exc:
+            print(f"ERROR {args.previous_snapshot}: cannot read previous snapshot: {exc}", file=sys.stderr)
+            return 1
+        if not isinstance(previous, dict):
+            print(f"ERROR {args.previous_snapshot}: previous snapshot must be a JSON object", file=sys.stderr)
+            return 1
+        snapshot = reconcile_discovery_snapshots(previous, snapshot)
     payload = json.dumps(snapshot, indent=2, sort_keys=True)
     if args.output:
         args.output.parent.mkdir(parents=True, exist_ok=True)
@@ -421,6 +433,15 @@ def _scan_repo(args: argparse.Namespace) -> int:
     candidates = snapshot["candidates"]
     review_count = len(snapshot.get("review_artifacts", []))
     review_summary = f", {review_count} review artifact(s)" if review_count else ""
+    diff = snapshot.get("reconciliation", {}).get("diff", {})
+    diff_summary = ""
+    if isinstance(diff, dict):
+        diff_summary = (
+            f", diff +{len(diff.get('added', []))}"
+            f"/~{len(diff.get('changed', []))}"
+            f"/-{len(diff.get('retired', []))}"
+            f"/!{len(diff.get('conflicted', []))}"
+        )
     mode = "dry-run " if args.dry_run else ""
     print(
         f"{mode}scan {snapshot['source']['repo_slug']} "
@@ -430,6 +451,7 @@ def _scan_repo(args: argparse.Namespace) -> int:
         f"{len(candidates['attributes'])} attribute(s), "
         f"{len(snapshot['replacement_scopes'])} replacement scope(s)"
         f"{review_summary}"
+        f"{diff_summary}"
     )
     if args.output:
         print(f"wrote {args.output}")