Give the interpreter real Celtic Cross meanings and --format/--lang support

- guidance.c now prints last, after the full spread; both it and main.c's
  new Celtic Cross readout pull real Waite card meanings via tarot_data.c
  instead of just naming cards.
- interpreter-cli gains --format text|html|json and --lang en|de, matching
  deck-engine - required linking engine/src/tarot_data.c and i18n.c into
  the interpreter binary (a narrow, documented exception to its earlier
  "no engine .c files" policy) and writing German translations for
  narrative.c's/guidance.c's own text.

interpreter/src/reading_io.c

@@ -22,6 +22,20 @@ static const char *const k_sign_slug[12] = {
   "libra", "scorpio", "sagittarius", "capricorn", "aquarius", "pisces",
 };
 
+/* Mirrors tarot_data.c's own k_card_slug/k_position_slug, same
+ * duplication policy as k_body_slug above. */
+static const char *const k_card_slug[TAROT_DECK_SIZE] = {
+  "fool", "magician", "high_priestess", "empress", "emperor", "hierophant",
+  "lovers", "chariot", "strength", "hermit", "wheel_of_fortune", "justice",
+  "hanged_man", "death", "temperance", "devil", "tower", "star", "moon",
+  "sun", "judgement", "world",
+};
+
+static const char *const k_position_slug[TAROT_SPREAD_SIZE] = {
+  "present", "challenge", "crown", "foundation", "recent_past",
+  "near_future", "attitude", "environment", "hopes_and_fears", "outcome",
+};
+
 static bool body_from_slug(const char *slug, Body *out) {
   for (int i = 0; i < NUM_BODIES; i++) {
     if (strcmp(slug, k_body_slug[i]) == 0) {
@@ -77,6 +91,48 @@ static bool aspect_type_from_slug(const char *slug, AspectType *out) {
   return false;
 }
 
+static bool card_from_slug(const char *slug, TarotCard *out) {
+  for (int i = 0; i < TAROT_DECK_SIZE; i++) {
+    if (strcmp(slug, k_card_slug[i]) == 0) {
+      *out = (TarotCard)i;
+      return true;
+    }
+  }
+  return false;
+}
+
+static bool position_from_slug(const char *slug, CelticCrossPosition *out) {
+  for (int i = 0; i < TAROT_SPREAD_SIZE; i++) {
+    if (strcmp(slug, k_position_slug[i]) == 0) {
+      *out = (CelticCrossPosition)i;
+      return true;
+    }
+  }
+  return false;
+}
+
+/* Fills out->positions[] from a "spread"."positions" JSON array. Used only
+ * for guidance_print()'s Attitude/Outcome framing, never for scoring, so
+ * this is deliberately lenient like parse_bodies(): an entry with an
+ * unrecognized/missing "position" or "card" slug is skipped, and a
+ * missing "spread" key entirely just leaves every position zeroed
+ * (card = the first enum value, reversed = false) rather than failing
+ * the whole load. */
+static void parse_spread(const JsonValue *positions, CelticCrossSpread *out) {
+  int count = json_array_count(positions);
+  for (int i = 0; i < count; i++) {
+    const JsonValue *item = json_array_get(positions, i);
+    CelticCrossPosition position;
+    TarotCard card;
+    if (!position_from_slug(json_as_string(json_object_get(item, "position")), &position)) continue;
+    if (!card_from_slug(json_as_string(json_object_get(item, "card")), &card)) continue;
+
+    out->positions[position].card = card;
+    const JsonValue *reversed = json_object_get(item, "reversed");
+    out->positions[position].reversed = reversed && reversed->type == JSON_BOOL && reversed->as.boolean;
+  }
+}
+
 bool reading_load_json(const char *text, size_t length, DailyReading *out) {
   memset(out, 0, sizeof(*out));
 
@@ -122,6 +178,9 @@ bool reading_load_json(const char *text, size_t length, DailyReading *out) {
   parse_bodies(natal ? json_object_get(natal, "bodies") : NULL, out->natal.bodies);
   parse_bodies(json_object_get(transits, "bodies"), out->transits.bodies);
 
+  const JsonValue *spread = json_object_get(root, "spread");
+  parse_spread(spread ? json_object_get(spread, "positions") : NULL, &out->spread);
+
   json_free(root);
   return ok;
 }