feat: replace strcpy/strcat with memcpy and add null-termination across multiple source files

Replace unsafe string concatenation patterns using strcpy/strcat with explicit memcpy calls and proper null-termination in bash_repair.c, context_manager.c, context_summarizer.c, and db.c. Add missing null-pointer checks for strdup results in bash_executor.c. Introduce atomic_int for spinner_running flag in http_client.c. Add consecutive_tool_error_iterations field to agent struct and refactor agent heartbeat/token tracking to use messages_get_db instead of db_open. Remove r_config_get_max_tokens declaration from r_config.h. Add json_repair.c to Makefile build sources and include db.h in messages.h with new messages_get_db function declaration.

include/messages.h

@@ -3,6 +3,7 @@
 #ifndef R_MESSAGES_H
 #define R_MESSAGES_H
 
+#include "db.h"
 #include "r_error.h"
 #include <json-c/json.h>
 #include <stdbool.h>
@@ -37,4 +38,6 @@ int messages_count(messages_handle msgs);
 
 char *messages_generate_session_id(void);
 
+db_handle messages_get_db(messages_handle msgs);
+
 #endif

include/r_config.h

@@ -24,7 +24,6 @@ bool r_config_is_verbose(r_config_handle cfg);
 void r_config_set_verbose(r_config_handle cfg, bool verbose);
 
 double r_config_get_temperature(r_config_handle cfg);
-int r_config_get_max_tokens(r_config_handle cfg);
 
 const char *r_config_get_session_id(r_config_handle cfg);
 bool r_config_set_session_id(r_config_handle cfg, const char *session_id);