wired: comma-separated VLAN lists cause false missing-VLAN alerts

@rslater-cs is already working on this.

Since Sep 9, 2026.

On CM5 bigbox firmware `bigbox-v1-cm-v0.11.2-2026-09-09T110059-v24.10.7`, the wired service incorrectly reports missing VLANs and enters `degraded` state.

The switch’s GE8 uplink reports:

```text
1UP, 4T, 8T, 32T, 100T
```

However, `parse_vlan_membership_string()` in `src/services/hal/backends/wired/providers/rtl8380m_http.lua:476` returns only VLAN 100.

The parser splits on whitespace, leaving trailing commas on earlier tokens. Its anchored pattern then rejects those tokens.

## Impact

False missing-VLAN alerts for admin VLAN 8, user VLAN 32, and WAN VLAN 4 on `switch-uplink-cm5`. Raw switch data contains all required VLANs; this finding does not establish a forwarding failure.

## Reproduction

Observed during a read-only inspection on 2026-09-09. Reproduced using source verified identical to the installed provider by SHA-256:

```text
78f919c72e4151b902e00b0ba07038d8792729efc31288803170029b970f35ba
```

| Input | Actual VLANs | Expected VLANs |
|---|---|---|
| `1UP, 4T, 8T, 32T, 100T` | `[100]` | `[1,4,8,32,100]` |
| `8T, 32T, 100UP` | `[100]` | `[8,32,100]` |
| `1UP 4T 8T 32T 100T` | `[1,4,8,32,100]` | `[1,4,8,32,100]` |

The first string comes from the GE8 uplink; the second also occurs on external switch ports. The whitespace-only case already parses correctly.

## Acceptance criteria

- [ ] Parse comma-separated and existing whitespace-separated memberships.
- [ ] Preserve tagged, untagged, forbidden, and PVID flags.
- [ ] Add regression coverage for both observed comma-separated strings and the whitespace-only case.
- [ ] Verify the three false trunk-carriage alerts disappear.