Printing tracking for owned copies and deck art, and an outdated-card-data notice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

@@ -210,6 +210,43 @@ pub struct DeckEntry {
     pub is_maybeboard: bool,
     /// Copies owned in the library (0 if the card isn't in the library).
     pub quantity_owned: i64,
+    /// The printing whose art this deck slot shows, if one was chosen. The
+    /// card's `image_uri`/`back_image_uri` already reflect it (falling back
+    /// to the default when the id no longer resolves).
+    pub preferred_scryfall_id: Option<String>,
+}
+
+/// One printing of a card, for the printing picker and copy labels.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct PrintingRef {
+    pub scryfall_id: String,
+    /// Scryfall's set code, lowercase (e.g. "2x2").
+    pub set_code: String,
+    pub collector_number: String,
+    /// Language code ("en", "ja", ...); empty on an older reference.db.
+    pub lang: String,
+    /// The finishes this printing exists in: "nonfoil", "foil", "etched".
+    pub finishes: Vec<String>,
+    pub rarity: String,
+    pub image_uri: String,
+    pub back_image_uri: String,
+    /// Scryfall's `prices.usd` for this printing, 0 if unknown.
+    pub price_usd: f64,
+    /// Release date as YYYY-MM-DD; empty on an older reference.db.
+    pub released_at: String,
+}
+
+/// A group of identical owned copies pinned to one printing + finish. Groups
+/// are a subset of the card's `quantity_owned`; copies not in any group are
+/// simply unspecified.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct LibraryCopy {
+    pub scryfall_id: String,
+    pub finish: String,
+    pub quantity: i64,
+    /// The printing's details, or `None` when the id no longer resolves in
+    /// the reference db (e.g. after a re-ingest dropped it).
+    pub printing: Option<PrintingRef>,
 }
 
 impl LibraryCard {