Align sized cluster seeds and GET dumps with PVE wire shapes; restyle DATA panel.

- Scale small/large/big seeds (3×50 / 10×1000 / 20×2000) with proportional
  backups, snapshots, HA, replication, Ceph capacity, and OSD totals
  (10 / 100 / 500) plus matching node disks and crush/pg metadata
- Enrich handler responses for apt, certificates, qemu/lxc status, storage,
  SDN, metrics export, and related cluster/node dumps
- Flatten nested body_example fields into PARAMS and sync the request body
  via dotted paths (oVirt-style)
- Restyle DATA controls as size cards with full-width Reset to minimal /
  Refresh stats; unload reloads the minimal cluster

tests/unit/test_backup_handlers.py

@@ -0,0 +1,126 @@
+"""Cluster backup job handlers."""
+
+from __future__ import annotations
+
+import json
+from typing import Any, cast
+
+from fastapi import FastAPI, Request
+
+from app.api.registry import HandlerRegistry
+from app.db.pool import AsyncpgDatabase
+from app.handlers.backup import register_backup_handlers
+
+
+class BackupPool:
+    def __init__(self) -> None:
+        self.metadata: dict[str, Any] = {
+            "backup_jobs": {
+                "backup-daily": {
+                    "id": "backup-daily",
+                    "schedule": "0 2 * * *",
+                    "storage": "local",
+                    "enabled": 1,
+                    "vmid": "100",
+                }
+            }
+        }
+        self.guests = [
+            {
+                "external_id": "100",
+                "kind": "qemu",
+                "state": '{"name":"demo"}',
+                "qemu_config": '{"scsi0":"local-lvm:vm-100-disk-0,size=32G"}',
+                "lxc_config": None,
+            },
+            {
+                "external_id": "200",
+                "kind": "lxc",
+                "state": '{"name":"service"}',
+                "qemu_config": None,
+                "lxc_config": '{"rootfs":"local-lvm:vm-200-disk-0,size=8G"}',
+            },
+        ]
+
+    async def fetchrow(self, query: str, *_arguments: object) -> dict[str, Any] | None:
+        if "FROM clusters WHERE id" in query:
+            return {"metadata": json.dumps(self.metadata)}
+        raise AssertionError(query)
+
+    async def fetch(self, query: str, *arguments: object) -> list[dict[str, Any]]:
+        if "FROM resources r" in query and "ANY($1" in query:
+            selected = set(str(item) for item in cast(list[Any], arguments[0]))
+            return [row for row in self.guests if row["external_id"] in selected]
+        if "FROM resources r" in query:
+            return list(self.guests)
+        raise AssertionError(query)
+
+    async def execute(self, query: str, *arguments: object) -> str:
+        if "UPDATE clusters SET metadata" in query:
+            self.metadata = json.loads(str(arguments[1]))
+            return "UPDATE 1"
+        raise AssertionError(query)
+
+
+def _request(pool: BackupPool) -> Request:
+    app = FastAPI()
+    app.state.database = cast(AsyncpgDatabase, type("DB", (), {"pool": pool})())
+    return Request(
+        {
+            "type": "http",
+            "app": app,
+            "method": "POST",
+            "path": "/",
+            "headers": [],
+            "query_string": b"",
+            "server": ("test", 80),
+            "client": ("test", 123),
+            "scheme": "http",
+        }
+    )
+
+
+async def test_backup_jobs_crud_and_shapes() -> None:
+    registry = HandlerRegistry()
+    register_backup_handlers(registry)
+    pool = BackupPool()
+    http = _request(pool)
+
+    listed = await registry.get("/cluster/backup", "GET")(http, {"values": {}})
+    assert listed[0]["id"] == "backup-daily"
+    assert listed[0]["schedule"] == "0 2 * * *"
+
+    await registry.get("/cluster/backup", "POST")(
+        http,
+        {
+            "values": {
+                "id": "backup-weekly",
+                "schedule": "@weekly",
+                "storage": "local",
+                "vmid": "200",
+            }
+        },
+    )
+    assert "backup-weekly" in pool.metadata["backup_jobs"]
+
+    info = await registry.get("/cluster/backup-info", "GET")(http, {"values": {}})
+    assert info == [{"subdir": "not-backed-up"}]
+
+    missing = await registry.get("/cluster/backup-info/not-backed-up", "GET")(http, {"values": {}})
+    assert missing == []  # 100 covered by daily; after weekly both covered? weekly adds 200
+    # daily covers 100, weekly covers 200 → none missing
+    assert missing == []
+
+    included = await registry.get("/cluster/backup/{id}/included_volumes", "GET")(
+        http, {"values": {"id": "backup-daily"}}
+    )
+    assert included["children"][0]["id"] == 100
+    assert included["children"][0]["children"][0]["id"] == "scsi0"
+
+    await registry.get("/cluster/backup/{id}", "DELETE")(http, {"values": {"id": "backup-weekly"}})
+    assert "backup-weekly" not in pool.metadata["backup_jobs"]
+    missing_after = await registry.get("/cluster/backup-info/not-backed-up", "GET")(
+        http, {"values": {}}
+    )
+    assert missing_after[0]["vmid"] == 200
+    assert missing_after[0]["type"] == "lxc"