Add guest info screen with backups, backup now and network

Press i on a guest to see its backups and network. Backups from every
backup-capable storage are listed newest first, with the backup jobs
that cover the guest. The network part shows the netN settings
(bridge, VLAN, MAC, IPv4/IPv6 setting, firewall) and the addresses in
use.

Press b in the info screen to back the guest up now: snapshot mode and
zstd, like the scheduled job, to a storage you pick (the job's storage
is preselected). It asks for confirmation, marks the guest busy and
uses --wait.

Fixed after review and a read-only live check:
- prune-backups arrives as a JSON string; parsing it as a dict
  crashed the app.
- CT addresses come from ip-addresses. inet6 holds only the
  link-local address, so the global SLAAC address was missing.
- The info screen uses the guest's live status, and odd API data
  (null size, unknown address types) no longer kills the app.
- The test fake now copies guest dicts; a shared constant was being
  mutated across tests.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/plans/guest-tui-mvp.md

@@ -236,3 +236,108 @@ VM consoles (serial/VNC), configurable SSH user/host/options, termproxy/websocke
 - [x] Interactive test by the user: `t` on CT 104, `exit`, back in the table; screen
       clean after the reset.
 - [ ] Push `feat/lxc-shell`, merge to `main` (user-approved).
+
+---
+
+# Guest info screen: backups, backup now, network (read-only) - delivery A
+
+## Problem
+
+Per guest, see its latest backups and network setup, and start a backup now. Network
+*editing* is delivery B (separate, live-tested), not part of this.
+
+## Decisions (user-approved)
+
+- Backup now uses the scheduled job's settings: `--mode snapshot --compress zstd`.
+  Storage is chosen from the node's backup-capable storages, preselected to the job's
+  storage (`truenas-backup` here), `local` as alternative.
+- Manual backups get `--notes-template "{{guestname}} (manual)"` so they are
+  recognisable. Note for the user: `truenas-backup` has storage prune `keep-all=1`, but
+  the job has `keep-last 3` per guest; a manual backup there likely counts towards it at
+  the job's next run (not verified).
+
+Observed CLI behaviour (cv4pve-cli 2.4.0, all read-only probes):
+
+- `get node storages <node> -o json` -> list of dicts: `storage`, `content`
+  (comma list, e.g. `iso,snippets,import,backup,vztmpl`), `enabled`, `active`, `type`,
+  `avail` (bytes).
+- `get cluster backup-jobs -o json` -> list of dicts: `id`, `enabled`, `storage`,
+  `schedule` (e.g. `mon,wed,fri 04:00`), `mode`, `compress`, `all` (1 = all guests),
+  `vmid` (comma list or null), `exclude` (comma list or null), `node` (null = all),
+  `next-run` (epoch), `prune-backups` (e.g. `{"keep-last":"3"}`).
+- `get guest backups <node> <storage> <vmid> -o json` -> list of dicts: `volid`
+  (`truenas-backup:backup/vzdump-lxc-104-2026_11_02-04_11_47.tar.zst`), `ctime` (epoch),
+  `size` (bytes), `format`, `notes`, `protected`, `subtype` (`lxc`|`qemu`), `vmid`.
+- `do backup guest <node> <vmid> <storage> [--key value]` - no `--yes` option.
+  vzdump params: `mode` snapshot|suspend|stop, `compress` 0|1|gzip|lzo|zstd,
+  `notes-template`.
+- CT net config: `netN` = `name=eth0,bridge=vmbr0,hwaddr=BC:24:11:36:DE:78,ip=dhcp,ip6=auto,type=veth`
+  (optional `gw`, `gw6`, `tag`, `firewall`, `rate`, `mtu`, ...).
+- VM net config: `netN` = `virtio=02:24:A6:49:A8:25,bridge=vmbr0[,tag=..][,firewall=1]`
+  (first item is `<model>=<MAC>`); IP settings live in `ipconfigN` (cloud-init), e.g.
+  `ip=dhcp`.
+- Runtime IPs, CT (running): `get ct interfaces <node> <vmid> -o json` -> list of
+  dicts: `name`, `hwaddr`, `inet` (e.g. `172.16.41.200/23`), `inet6` (may be absent/
+  null), `ip-addresses` (JSON string).
+- Runtime IPs, VM (running, guest agent): `get vm agent network <node> <vmid> -o json`
+  -> `[{"key": "result", "value": "<JSON string>"}]`; the JSON is a list of
+  `{"name", "hardware-address", "ip-addresses": [{"ip-address", "prefix",
+  "ip-address-type": "ipv4"|"ipv6"}]}`. Fails when the agent is not running.
+
+### `cli.py`
+
+- `backup_storages(guest) -> list[str]` - storages on the guest's node whose `content`
+  contains `backup` and that are enabled and active, in API order.
+- `backup_jobs() -> list[dict]`.
+- `job_storage(jobs, guest) -> str | None` - storage of the first enabled job covering
+  the guest: (`all` truthy and vmid not in `exclude`) or vmid in `vmid`; and `node` null
+  or equal to the guest's node.
+- `backup_jobs()` parses `prune-backups` when the CLI returns it as a JSON string
+  (real output: `'{"keep-last":"3"}'`).
+- `backups(guest, storages) -> list[dict]` - all backups of the guest on those
+  storages, newest first (`ctime` desc). Each dict gets `storage` (from volid prefix).
+- `backup_now(guest, storage)` -> `do backup guest <node> <vmid> <storage> --mode
+  snapshot --compress zstd --notes-template "{{guestname}} (manual)" --wait`.
+- `parse_net(value: str) -> dict` - `netN` string to an ordered dict of key -> value
+  (insertion order kept, so B can re-serialise unchanged keys). VM: the first
+  `<model>=<MAC>` item is kept as is (key = model).
+- `nets(config) -> dict[str, dict]` - `netN` keys (sorted by N) -> `parse_net(value)`.
+- `interfaces(guest) -> list[dict]` - runtime interfaces as
+  `{"name", "mac", "ipv4": [cidr...], "ipv6": [cidr...]}`, loopback (`lo`) excluded.
+  CT via `get ct interfaces` (addresses from its `ip-addresses` JSON string - `inet6`
+  alone holds only one, e.g. link-local, and misses the global SLAAC address), VM via
+  `get vm agent network`. Only called when the guest's live status is running.
+
+### `app.py` (UI contract)
+
+- Key `i` on a guest opens `InfoScreen(guest)` (a `Screen` or `ModalScreen`). Empty
+  table: nothing.
+- InfoScreen loads in a thread worker: config -> `cli.nets`, `cli.interfaces` (only if
+  status is `running`; a failure there is shown inline as "unavailable: <summary>", not
+  as a fatal error), `cli.backup_storages`, `cli.backup_jobs`, `cli.backups`.
+- Shows:
+  - `DataTable#backups`: Date (local time, `YYYY-MM-DD HH:MM`), Storage, Size (GiB, one
+    decimal), Format, Notes. Newest first. A `Static#jobs` line naming the job(s) that
+    cover the guest (schedule, storage, `keep-last` if present) or "No backup job
+    covers this guest".
+  - `DataTable#nets`: Iface (net0...), Bridge, VLAN (`tag` or `-`), MAC, IPv4 (CT `ip`,
+    VM `ipconfigN` `ip`, or `-`), IPv6 (CT `ip6`, VM `ipconfigN` `ip6`, or `-`),
+    Firewall (`yes`/`no`).
+  - `DataTable#addresses`: Interface, MAC, IPv4, IPv6 (runtime), or the unavailable
+    line.
+- Key `b` in InfoScreen: `BackupScreen` modal with `Select#storage` (options =
+  backup storages, preselected `job_storage` or the first), text saying mode snapshot,
+  zstd, and the guest; buttons `#yes` / `#no`; escape = no. On yes: guest marked busy
+  in `app.busy` (refuse with a warning if already busy), "backup started" notify, worker
+  runs `cli.backup_now`, then "backup done"/error notify, busy released, backup list
+  reloaded if the InfoScreen is still open.
+- `escape` closes InfoScreen; `g` in InfoScreen reloads it.
+- Every CLI failure -> error notify with `_message(exc)`, app keeps running.
+
+## Steps
+
+- [x] Tests (cli + UI contract) - red first.
+- [x] Implementation - suite green, ruff clean, README keys `i` / `b`.
+- [x] Read-only live check: open InfoScreen for CT 104 and VM 108, data shown.
+- [ ] User tests "Backup now" on CT 104.
+- [ ] Push `feat/guest-info`, merge to `main` (user-approved after the test).