feat(uns-loader): verify-equipment — recursive Equipment UNS tree browse + leaf count

browse_summary assumes the flat 2-level Galaxy hierarchy; the Equipment tree is deep
(Area/Line/Equipment/[FolderPath]/Signal). Add browse_tree (recursive leaf descent) + a
verify-equipment subcommand that reports/asserts the leaf signal count (--expect N), for
verifying OtOpcUa equipment-namespace structure materialisation. Smoke-tested against a live
:4840 (40 folders / 396 leaf signals).

otopcua-uns-loader/otopcua_uns.py

@@ -298,6 +298,64 @@ def sample_values(endpoint, n):
         return [("<browse error>", str(e), "?")]
 
 
+def browse_tree(endpoint, max_depth=8):
+    """Recursively descend the OtOpcUa address space and count leaf variables, returning
+    (folder_count, leaf_count, leaf_paths). A node with no children is a leaf signal — this
+    correctly handles the DEEP Equipment UNS tree (Area/Line/Equipment/[FolderPath]/Signal),
+    unlike browse_summary which assumes the flat 2-level Galaxy hierarchy."""
+    import asyncio
+    from asyncua import Client
+
+    async def walk(node, path, depth, acc):
+        if depth >= max_depth:
+            return
+        for ch in await node.get_children():
+            try:
+                name = (await ch.read_browse_name()).Name
+            except Exception:
+                continue
+            child_path = path + "/" + name
+            grandkids = await ch.get_children()
+            if grandkids:
+                acc["folders"] += 1
+                await walk(ch, child_path, depth + 1, acc)
+            else:
+                acc["leaves"] += 1
+                acc["paths"].append(child_path)
+
+    async def run():
+        acc = {"folders": 0, "leaves": 0, "paths": []}
+        async with Client(endpoint) as c:
+            for k in await c.nodes.objects.get_children():
+                if (await k.read_browse_name()).Name != "OtOpcUa":
+                    continue
+                await walk(k, "OtOpcUa", 0, acc)
+        return acc["folders"], acc["leaves"], acc["paths"]
+    try:
+        return asyncio.run(run())
+    except Exception as e:
+        return (f"<{type(e).__name__}: {e}>", 0, [])
+
+
+def cmd_verify_equipment(args):
+    """Browse the full UNS tree by friendly Area/Line/Equipment/Signal names and report the leaf
+    signal count. With --expect N, exit non-zero unless exactly N leaf signals are present (the
+    equipment-namespace structure-materialisation check)."""
+    folders, leaves, paths = browse_tree(args.opcua_endpoint)
+    print(f"equipment tree : {folders} folder(s), {leaves} leaf signal(s) on {args.opcua_endpoint}")
+    for p in sorted(paths)[:args.show]:
+        print(f"    {p}")
+    if len(paths) > args.show:
+        print(f"    … and {len(paths) - args.show} more")
+    if args.expect is not None:
+        passed = leaves == args.expect
+        print("VERIFY-EQUIPMENT:",
+              f"PASS ({leaves} == {args.expect})" if passed
+              else f"FAIL (expected {args.expect}, found {leaves})")
+        return 0 if passed else 1
+    return 0
+
+
 # ── arg parsing ─────────────────────────────────────────────────────────────
 def main(argv):
     p = argparse.ArgumentParser(description="Reloadable populate + verify for the OtOpcUa galaxy UNS.")
@@ -318,13 +376,17 @@ def main(argv):
     vp = sub.add_parser("verify")
     vp.add_argument("--wait", action="store_true", help="poll until the deploy lands")
     vp.add_argument("--wait-seconds", type=int, default=120)
+    ep = sub.add_parser("verify-equipment",
+                        help="recursively browse the Equipment UNS tree + count leaf signals")
+    ep.add_argument("--expect", type=int, default=None, help="assert exactly N leaf signals")
+    ep.add_argument("--show", type=int, default=20, help="how many leaf paths to print")
 
     a = p.parse_args(argv)
     a.mssql = dict(host=a.sql_host, port=a.sql_port, user=a.sql_user,
                    password=a.sql_password, database=a.sql_db)
     return {
         "generate": cmd_generate, "populate": cmd_populate, "clean": cmd_clean,
-        "status": cmd_status, "verify": cmd_verify,
+        "status": cmd_status, "verify": cmd_verify, "verify-equipment": cmd_verify_equipment,
     }[a.cmd](a)