Printing tracking for owned copies and deck art, and an outdated-card-data notice

Owned copies can now be pinned to a printing + finish (nonfoil / foil /
etched), activating the long-dormant library_card_copies table as groups
of identical copies. library_cards.quantity_owned stays authoritative:
groups are a subset of it, and the rest are "unspecified". Tracking more
copies than are unspecified grows ownership to fit; lowering ownership
trims the most recently added groups first. Migration 0006 adds the
group quantity, a unique (card, printing, finish) index, and
deck_cards.preferred_scryfall_id.

A deck slot can show a chosen printing's art, both faces from that
printing, falling back to the default when the id no longer resolves.
It survives quantity/board changes and is kept by duplicate_deck.

UI: the click preview's info tile gets a Printings section when opened
from the Library or a deck (copy groups with steppers, "Add a
printing…", and "Shown in this deck" with Change…/Default), backed by a
printing picker grid. The picker takes Escape in the capture phase so
it closes without closing the preview under it.

Sync: CardEntry.printings (keyed "<scryfall_id>/<finish>") and
DeckCardEntry.printing. Cards now merge field by field with groups per
key, so a quantity edit and a printing added on another device both
survive; merged groups are clamped deterministically. A document is
written as version 2 only once it holds printing data, so older builds
and servers refuse it instead of dropping the data and syncing the loss.

Decklists: "(SET) NUM", optionally "*F*"/"*E*", round-trips through deck
and library export/import. Library export writes a line per group plus
one for unspecified copies.

reference.db printings gain lang and released_at for picker labels and
ordering. When the installed card data lacks any column this build's
reference schema has (found by diffing against the schema applied
in-memory, so no list to maintain), a notice under the top bar offers
Update card data (and Import card data… on phones); "Not now" is
remembered until something more goes missing.

src-tauri/src/lib.rs

@@ -99,6 +99,10 @@ pub fn run() {
             commands::deck_contents,
             commands::suggest_cards,
             commands::card_decks,
+            commands::list_printings,
+            commands::list_library_copies,
+            commands::set_library_copy,
+            commands::set_deck_card_printing,
             commands::export_deck,
             commands::import_deck,
             commands::export_library_cards,