add missinng context initialization

src/rvprof_context.c

@@ -1,5 +1,23 @@
 #include "rvprof_internal.h"
 
+// initialize with basic defaults - environment variables will override these
+rvprof_context_t g_rvprof = {
+    .config = {
+        .enable_hooks = 1,               // Default: enable hooks
+        .merge_regions = 1,              // Default: merge regions
+        .output_filename = NULL,         // Auto-generate
+        .program_name = NULL             // Auto-detect
+    },
+    .use_cycles = 1,                     // Try cycle counter first
+    .stack_ptr = -1,                     // No active regions
+    .initialized = 0,                    // Not initialized
+    .auto_initialized = 0,               // Not auto-initialized
+    .symbols_loaded = 0,                 // No symbols loaded
+    .total_program_time = 0,
+    .total_program_cycles = 0,
+    .total_memory_allocated = 0
+};
+
 void rvprof_context_cleanup(void){
     if (!g_rvprof.initialized) {
         return;