feat: add agent policies and session typeFilter fallbacks

- fetch_jobs: try /api/v1/agents/policies/states and /api/v1/agents/policies
  as additional fallback URLs (agent-based backup policies)
- fetch_sessions: fallback with typeFilter=Backup and typeFilter=Agent
  to find actual backup/agent sessions beyond system config sync
- New fetch_agent_policies() method for dedicated agent policy queries
- Helps surface real backup policies when classic /api/v1/jobs fails
  due to FileBackup enum bug

veeam_client.py

@@ -211,6 +211,8 @@ class VeeamClient:
                 "/api/v1/jobs?source=Backup",
                 "/api/v1/jobs/states?typeFilter=Backup",
                 "/api/v1/jobs?typeFilter=Backup",
+                "/api/v1/agents/policies/states",
+                "/api/v1/agents/policies",
             ):
                 try:
                     return await self._fetch_json_list(path)
@@ -232,12 +234,21 @@ class VeeamClient:
                         return [self._normalize_legacy_job(j) for j in jobs]
             except Exception:
                 pass
-            raise ConnectionError("all job endpoints failed (v12 REST + legacy XML)")
+            raise ConnectionError("all job/policy endpoints failed (v12 REST + legacy XML)")
         return await self._fetch_legacy_jobs()
 
     async def fetch_sessions(self, limit: int = 50) -> list[dict]:
         if self._is_v12():
-            return await self._fetch_json_list(f"/api/v1/sessions?limit={limit}")
+            for path in (
+                f"/api/v1/sessions?limit={limit}",
+                f"/api/v1/sessions?limit={limit}&typeFilter=Backup",
+                f"/api/v1/sessions?limit={limit}&typeFilter=Agent",
+            ):
+                try:
+                    return await self._fetch_json_list(path)
+                except Exception:
+                    continue
+            return []
         return await self._fetch_legacy_sessions(limit)
 
     async def fetch_repositories(self) -> list[dict]:
@@ -265,6 +276,18 @@ class VeeamClient:
             return await self._fetch_json_list("/api/v1/agents/protectedComputers")
         return []
 
+    async def fetch_agent_policies(self) -> list[dict]:
+        if self._is_v12():
+            for path in (
+                "/api/v1/agents/policies/states",
+                "/api/v1/agents/policies",
+            ):
+                try:
+                    return await self._fetch_json_list(path)
+                except Exception:
+                    continue
+        return []
+
     async def _fetch_json_list(self, path: str) -> list[dict]:
         resp = await self._http.get(
             f"{self.base_url}{path}",