Add core engine: tarot + astrology reading generator with CLI and i18n

Plain-C, dependency-free engine that produces a personalized daily
Celtic Cross tarot spread and natal-chart/transit astrology reading,
plus a standalone CLI (dist/deck-engine) and run.sh wrapper. Includes
English/German output via a simple key=value translation format, and
docs/diagrams describing the architecture and I/O.

.gitignore

@@ -0,0 +1,10 @@
+# Build output, including dist/user.properties which holds real birth
+# data once filled in — never commit it.
+/dist
+/engine/build
+
+*.o
+core
+core.*
+
+.DS_Store