item claim lifecycle: town claim window with stash-or-discard

[zgeoff]

Settled loot currently just accumulates; this adds a claim step — a town window where settled items are accepted into the stash or discarded.

Draft — whether claiming exists at all, and where it lives, hangs on the town and itemisation game design; treat every behavior below as provisional.

Player story

You return to town and a window holds the loot your runs have settled since you last checked. You pull what you want into your stash and discard the rest; a discarded item never reappears and never gets in the way of future drops. Rebooting mid-claim loses nothing — the window opens on the same unclaimed loot. You never claim an item twice, never lose one you stashed, and never have to claim in a hurry: loot waits indefinitely. In one sentence: your loot waits in town until you decide what's worth keeping.

Scope

• a lifecycle state on minted items — unclaimed, stashed, discarded — flagged in place, never deleted (an item's identity is its lineage and later systems may reference it)
• idempotent, owner-scoped claim and discard mutation procedures
• an unclaimed-items read backing the window (partial index over the unclaimed state)
• the town claim window screen (workable-only presentation)

Notes

• Blocked by avatar item inventory: the listing read and the real stash panel #576 (inventory listing) and rolled-reward coordinates and the reveal path #469 (mint and reveal path).
• Claiming is presentation/ownership state layered on settled rows — mint identity, content, and the entropy model are untouched.
• Non-goals: trade, item detail views, bulk-claim UX polish.