feat: implement and exhaustively test the game domain core

include/fleet_generator.h

@@ -3,4 +3,12 @@
 #include "app_interfaces.h"
 #include "game_types.h"
 
+enum {
+  kFleetPlacementAttempts = 128,
+  kFleetGenerationRestarts = 64,
+};
+
 typedef struct { random_source_t random; } fleet_generator_t;
+
+bool fleet_generator_generate(const fleet_generator_t *generator, board_t *board);
+bool fleet_generator_validate(const board_t *board);