Printing tracking for owned copies and deck art, and an outdated-card-data notice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

crates/mtgc-core/src/sql/library/0006_printings.sql

@@ -0,0 +1,15 @@
+-- v6 — optional per-printing tracking (see docs/printing-tracking-design.md).
+--
+-- `library_card_copies` has existed since v1 but was never written. Each row now
+-- means "`quantity` of my copies of this card are this printing + finish": a
+-- group of identical copies rather than one row per physical card. Groups are
+-- a subset of `library_cards.quantity_owned`, which stays authoritative for
+-- totals; any copies not covered by a group are simply unspecified.
+ALTER TABLE library_card_copies ADD COLUMN quantity INTEGER NOT NULL DEFAULT 1;
+CREATE UNIQUE INDEX idx_copies_printing
+    ON library_card_copies(library_card_id, scryfall_id, finish);
+
+-- Which printing's art to show for a deck slot. A pure display preference:
+-- printings live in the rebuildable reference.db, so there's no foreign key,
+-- and an id that no longer resolves just falls back to the default image.
+ALTER TABLE deck_cards ADD COLUMN preferred_scryfall_id TEXT;

crates/mtgc-core/src/sql/reference_schema.sql

@@ -94,7 +94,11 @@ CREATE TABLE IF NOT EXISTS printings (
     -- Boolean: this printing isn't available on paper (Scryfall `games`).
     digital          INTEGER NOT NULL DEFAULT 0,
     -- Boolean: this printing comes from a "funny" set (Scryfall `set_type`).
-    funny            INTEGER NOT NULL DEFAULT 0
+    funny            INTEGER NOT NULL DEFAULT 0,
+    -- Scryfall language code ("en", "ja", ...) and release date (YYYY-MM-DD),
+    -- for labelling and ordering printings in the printing picker.
+    lang             TEXT NOT NULL DEFAULT '',
+    released_at      TEXT NOT NULL DEFAULT ''
 );
 CREATE INDEX IF NOT EXISTS idx_printings_oid ON printings(oracle_id);