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.

engine/scripts/run-interpreter.sh

@@ -3,6 +3,12 @@
 # "today": same OS-clock seed/transit-moment and user.properties birth
 # data as run-engine.sh, but reports how significant today's transits are
 # instead of printing the full reading. Usage: ./run-interpreter.sh
+# [text|html|json] [lang]
+#
+# [lang] overrides user.properties' lang= for this run only, same as
+# run-engine.sh - but note it only affects interpreter-cli's own output;
+# deck-engine is always run without --lang here, since --format json is
+# deliberately language-independent (see docs/input-output-format.md).
 #
 # Requires both dist/deck-engine (built by engine/'s Makefile) and
 # dist/interpreter-cli (built by interpreter/'s own Makefile) to already
@@ -35,6 +41,7 @@ birth_time=""
 birth_utc_offset=""
 birth_lat=""
 birth_lon=""
+lang="en"
 
 while IFS='=' read -r key value || [ -n "$key" ]; do
   key="$(printf '%s' "$key" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')"
@@ -48,6 +55,7 @@ while IFS='=' read -r key value || [ -n "$key" ]; do
     birth_utc_offset) birth_utc_offset="$value" ;;
     birth_lat) birth_lat="$value" ;;
     birth_lon) birth_lon="$value" ;;
+    lang) [ -n "$value" ] && lang="$value" ;;
   esac
 done <"$PROPERTIES_FILE"
 
@@ -67,10 +75,13 @@ check_set birth_lon "$birth_lon"
 
 # OS-provided inputs: today's date is the tarot seed (stable all day, a
 # new spread each day), current UTC time drives today's transits. The
-# tarot seed doesn't matter for --format json (only "transits" is read
-# downstream) but it's kept identical to run-engine.sh's for consistency.
+# tarot seed still matters for --format json now that "spread" is read
+# downstream too (guidance.c's Attitude/Outcome framing) - kept identical
+# to run-engine.sh's for consistency either way.
 seed="$(date +%Y-%m-%d)"
 transit_date="$(date -u +%Y-%m-%dT%H:%M)"
+format="${1:-text}"
+lang="${2:-$lang}"
 
 "$ENGINE_BINARY" \
   --seed "$seed" \
@@ -81,4 +92,4 @@ transit_date="$(date -u +%Y-%m-%dT%H:%M)"
   --birth-lon "$birth_lon" \
   --date "$transit_date" \
   --format json \
-  | exec "$INTERPRETER_BINARY"
+  | exec "$INTERPRETER_BINARY" --format "$format" --lang "$lang" --i18n-dir "$SCRIPT_DIR/i18n"