refactor: restructure core module into domain-driven packages with 2672 insertions and 2220 deletions

Splits monolithic core module into bounded contexts: identity, billing, and notification domains. Moves entity definitions, repository interfaces, and service implementations into separate packages. Updates import paths across 25 files to align with new package structure. Removes cross-domain coupling by extracting shared value objects into a common package.

.backup.1.rinterp.c

@@ -0,0 +1,40 @@
+#include "rlexer.c";
+
+typedef enum rip_ast_type_t { RIP_NONE = 0, RIP_BLOCK, RIP_CALL, RIP_LITERAL } rip_ast_type_t;
+
+typedef struct rip_ast_t {
+    struct rip_ast_t *children;
+    struct rip_ast_t *next;
+    struct rip_ast_t *previous;
+    rip_ast_type_t type;
+} rip_ast_t;
+
+rip_ast_t *rip_ast_new() {
+    rip_ast_t *ast = (rip_ast_t *)malloc(sizeof(rip_ast_t));
+    ast->children = NULL;
+    ast->next = NULL;
+    ast->previous = NULL;
+    ast->type = RIP_NONE;
+    return ast;
+}
+
+rip_ast_t *rip_parse() {
+    rtoken_t token = rlex_next();
+    if (token.type == RT_CURLY_BRACE_OPEN) {
+        rip_ast_t *ast = rip_ast_new();
+        while ()
+            rip_ast_t *statement = rip_parse();
+    }
+}
+
+int main() {
+
+    char *script = "{print(\"test\")}";
+    rlex(script);
+    while (true) {
+        rtoken_t token = rlex_next();
+        if (token.type = RT_CURLY_BRACE_OPEN) {
+            rclos
+        }
+    }
+}