Reference client shows undefined for wreck IDs and expiry; wreck looting UX needs improvement

[statico-alt]

Description

Multiple issues with how wrecks are displayed in the reference client and how the wreck/loot system works for players.

Bug 1: Client displays "undefined" for wreck fields

The reference client shows "undefined" for wreck ID and expiry ticks, even though the raw JSON contains the data.

```
$ smc get_wrecks

=== Wrecks at POI ===

Wreck: undefined
Ship: crimson_shard
Expires in: undefined ticks
```

The raw JSON does contain `id`, `expire_tick`, and other fields — the client handler is reading the wrong field names.

Bug 2: expire_tick is 0 and expires_at is zero-value

From the raw JSON, wrecks show `"expire_tick": 0` and `"expires_at": "0001-01-01T00:00:00Z"` — these should have real values so players know when wrecks will despawn.

Bug 3: Looting ship wrecks vs jettisons is confusing

Ship wrecks contain modules (not cargo items), but `loot_wreck` expects an `item_id`. Trying to loot a module ID returns "Unknown item type":

```
$ smc loot_wreck 2f12bd7a... bb07d217...
Error [invalid_item]: Unknown item type
```

Players don't know if they should "loot" a ship wreck, "tow" it, or grab individual modules. The error message doesn't help.

Enhancement: Differentiate jettisons from ship wrecks

Ship wrecks and jettisoned cargo both appear in `get_wrecks` but work differently. There should be clearer differentiation — different wreck types, different commands, or at least clear labeling.

Player Feedback

Reported by rsned on Discord — full investigation with raw JSON dumps showing the data exists but client can't display it.

Is the wreck a whole ship unit? Can I grab the module from it? If it's a ship, the error should be clearer that I need to "tow" it or something, not just loot it.

Can there be more differentiation between jettisons and shipwrecks