Add LLDP collect page with conservative fabric edge lifecycle.

Move scheduled discovery under Network → LLDP links, mark absent edges missing after one successful scan, purge only after four miss cycles, and expose unmatched/raw job detail.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_lldp_collect.py

@@ -0,0 +1,65 @@
+"""LLDP collect policy / dashboard (network topology management)."""
+
+from __future__ import annotations
+
+import unittest
+from uuid import uuid4
+
+from netx_api.db import Base, SessionLocal, engine
+from netx_api.lldp_collect_schemas import LldpCollectPolicyUpdate
+from netx_api.lldp_collect_service import (
+    ensure_policy,
+    get_dashboard,
+    next_due_at,
+    update_policy,
+)
+from netx_api.models import LldpCollectPolicy
+
+
+class LldpCollectTests(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls) -> None:
+        Base.metadata.create_all(bind=engine)
+
+    def setUp(self) -> None:
+        self.db = SessionLocal()
+        self.db.query(LldpCollectPolicy).delete()
+        self.db.commit()
+
+    def tearDown(self) -> None:
+        # Do not leave scheduled collect enabled in shared DB.
+        row = self.db.get(LldpCollectPolicy, 1)
+        if row is not None:
+            row.enabled = False
+            self.db.commit()
+        self.db.close()
+
+    def test_policy_defaults_disabled(self) -> None:
+        row = ensure_policy(self.db)
+        self.assertEqual(row.id, 1)
+        self.assertFalse(row.enabled)
+        dash = get_dashboard(self.db)
+        self.assertFalse(dash.policy.enabled)
+        self.assertIsNone(dash.next_due_at)
+
+    def test_policy_enable_updates(self) -> None:
+        ensure_policy(self.db)
+        out = update_policy(
+            self.db,
+            LldpCollectPolicyUpdate(
+                enabled=True,
+                interval_days=2,
+                concurrency=6,
+                scope_mode="all",
+                auto_add_unmatched=True,
+            ),
+        )
+        self.assertTrue(out.enabled)
+        self.assertEqual(out.interval_days, 2)
+        self.assertEqual(out.concurrency, 6)
+        due = next_due_at(self.db, ensure_policy(self.db))
+        self.assertIsNotNone(due)
+
+
+if __name__ == "__main__":
+    unittest.main()