Add a Card Search tab and fix horizontal-card (Battle/Plane) preview orientation

Card Search browses the whole downloaded card universe (not just owned
cards), reusing the Library tab's filter/group/sort/list/tiles UI; results
show ownership and offer quick "own" and "add to deck" actions.

Battles, Planes, and Phenomena store their Scryfall image portrait-shaped
with the content itself rotated, so hover/click previews now detect this
(a new `horizontal` flag threaded through ingest and every card query, with
graceful fallback for a reference.db built before the column existed) and
rotate the image back into place. Single-faced and non-DFC cases are
verified fixed; a double-faced Battle's front face still needs another pass.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

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

@@ -15,7 +15,8 @@ CREATE TABLE IF NOT EXISTS oracle_cards (
     produces_colorless INTEGER NOT NULL DEFAULT 0,  -- boolean: can produce {C}
     legalities         INTEGER NOT NULL DEFAULT 0,  -- 2 bits/format x 8 formats, see model::LEGALITY_FORMATS
     themes             INTEGER NOT NULL DEFAULT 0,  -- archetype bitmask, see synergy::ARCHETYPES
-    edhrec_rank        INTEGER                      -- Scryfall EDHREC popularity rank; NULL if unranked
+    edhrec_rank        INTEGER,                     -- Scryfall EDHREC popularity rank; NULL if unranked
+    horizontal         INTEGER NOT NULL DEFAULT 0   -- boolean: printed/displayed sideways (Scryfall layout "battle"/"planar")
 );
 CREATE INDEX IF NOT EXISTS idx_oracle_name_lower ON oracle_cards(name_lower);
 CREATE INDEX IF NOT EXISTS idx_oracle_ci ON oracle_cards(color_identity);