Add a vanilla-creature filter to card and library search

Filtering for creatures with an empty rules box can't be done from
`oracle_cards.oracle_text`: that column joins every face together, so an
Adventure card always carries its spell half's text and a naive `oracle_text
= ''` test would exclude exactly the cards worth including.

Derive it at ingest instead, from the front face's own text — the front is the
half that resolves as the creature, and adventure/prepared/transform cards are
all cast from it. Exposed as `vanilla_only` behind its own `has_vanilla`
capability check rather than folded into `has_universes_beyond`, since it
lands in a later reference-schema revision and a db can have one column
without the other. Needs a card-data re-download before it does anything.

src/components.tsx

@@ -1449,6 +1449,13 @@ const ICON_CROWN = icon(
     <line x1="5" y1="21" x2="19" y2="21" />
   </>,
 );
+/** An empty rules box — a vanilla creature, all body and no text. */
+const ICON_BLANK_BOX = icon(
+  <>
+    <rect x="3" y="4" width="18" height="16" rx="2" />
+    <line x1="3" y1="9" x2="21" y2="9" />
+  </>,
+);
 
 /**
  * Card-origin and numeric criteria shared by the Library and Card Search
@@ -1467,6 +1474,7 @@ export type CardCriteria = {
   priceMax: string;
   legalIn: string;
   canBeCommander: boolean;
+  vanillaOnly: boolean;
   powerMin: string;
   powerMax: string;
   toughMin: string;
@@ -1481,6 +1489,7 @@ export const EMPTY_CRITERIA: CardCriteria = {
   priceMax: "",
   legalIn: "",
   canBeCommander: false,
+  vanillaOnly: false,
   powerMin: "",
   powerMax: "",
   toughMin: "",
@@ -1511,6 +1520,7 @@ export function applyCardCriteria(c: CardCriteria): Partial<LibraryFilter> {
     price_max: num(c.priceMax),
     legal_in: c.legalIn || null,
     can_be_commander: c.canBeCommander,
+    vanilla_only: c.vanillaOnly,
     power_min: num(c.powerMin),
     power_max: num(c.powerMax),
     toughness_min: num(c.toughMin),
@@ -1529,6 +1539,7 @@ export function applyCardCriteria(c: CardCriteria): Partial<LibraryFilter> {
 export function criteriaActive(c: CardCriteria): boolean {
   return (
     c.canBeCommander ||
+    c.vanillaOnly ||
     c.legalIn !== "" ||
     [c.priceMin, c.priceMax, c.powerMin, c.powerMax, c.toughMin, c.toughMax].some(
       (v) => v.trim() !== "",
@@ -1663,6 +1674,13 @@ export function CardCriteriaFields({
             on={c.canBeCommander}
             onToggle={() => onChange({ canBeCommander: !c.canBeCommander })}
           />
+          <IconToggle
+            icon={ICON_BLANK_BOX}
+            label="Only vanilla creatures"
+            hint="Creatures with an empty rules box. Includes Adventure and Prepared cards whose creature half has no abilities."
+            on={c.vanillaOnly}
+            onToggle={() => onChange({ vanillaOnly: !c.vanillaOnly })}
+          />
         </div>
       </div>
     </>