fix: reformat codebase and fix const-correctness for CI lint

- Reformat all C/H files to match .clang-format (LLVM style)
- Fix 26 cppcheck const-correctness warnings (constParameterPointer,
  constVariablePointer, constVariable)
- Update function declarations in headers to match const parameters

src/server/server.c

@@ -16,21 +16,24 @@
 #include <stdlib.h>
 #include <string.h>
 
-int receive_files(Config *config, int fd) {
+int receive_files(Config* config, int fd) {
   Status status;
-  if (!receive_status(fd, &status)) return -1;
+  if (!receive_status(fd, &status))
+    return -1;
 
   while (status == STATUS_NEXT || status == STATUS_CHUNK || status == STATUS_CHECK) {
     if (status == STATUS_CHECK) {
       bool skipped;
-      File *file = receive_incremental_check(fd, config, &skipped);
-      if (skipped) goto next;
-      if (file == NULL && !skipped) return -1;
+      File* file = receive_incremental_check(fd, config, &skipped);
+      if (skipped)
+        goto next;
+      if (file == NULL && !skipped)
+        return -1;
       if (config->save_to_disk)
         file_save_to_disk(config->receive_root_directory, file);
       file_destroy(file);
     } else if (status == STATUS_CHUNK) {
-      Chunk *chunk = receive_chunk_data(fd, config);
+      Chunk* chunk = receive_chunk_data(fd, config);
       if (chunk == NULL) {
         send_status(fd, STATUS_ERROR);
         return -1;
@@ -41,7 +44,7 @@ int receive_files(Config *config, int fd) {
       }
       chunk_destroy(chunk);
     } else {
-      File *file = file_receive(config, fd);
+      File* file = file_receive(config, fd);
       if (file == NULL) {
         log_message(LOG_LEVEL_ERROR, "Failed to receive file");
         send_status(fd, STATUS_ERROR);
@@ -59,7 +62,8 @@ int receive_files(Config *config, int fd) {
   }
 
   if (status == STATUS_MANIFEST) {
-    if (receive_manifest(fd, config, &status) != 0) return -1;
+    if (receive_manifest(fd, config, &status) != 0)
+      return -1;
   }
   if (status != STATUS_FINISHED) {
     log_message(LOG_LEVEL_ERROR, "Did not receive FINISHED Status");
@@ -71,21 +75,20 @@ int receive_files(Config *config, int fd) {
 }
 
 void handler(int file_descriptor) {
-  Config *config = config_receive(file_descriptor);
+  Config* config = config_receive(file_descriptor);
   if (config == NULL) {
     log_message(LOG_LEVEL_ERROR, "Failed to receive config");
     close(file_descriptor);
     return;
   }
   if (config->use_multithreading) {
-    Queue *q = queue_create(100, file_destroy);
+    Queue* q = queue_create(100, file_destroy);
     if (q == NULL) {
       config_delete(config);
       close(file_descriptor);
       return;
     }
-    PipelineContextReceiver *context = pipeline_context_receiver_create(
-        config, q, file_descriptor);
+    PipelineContextReceiver* context = pipeline_context_receiver_create(config, q, file_descriptor);
     if (context == NULL) {
       queue_destroy(q);
       config_delete(config);
@@ -109,7 +112,7 @@ void handler(int file_descriptor) {
   close(file_descriptor);
 }
 
-static Server *g_server = NULL;
+static Server* g_server = NULL;
 
 static void cleanup(int sig) {
   (void)sig;
@@ -134,11 +137,11 @@ static void print_server_usage(void) {
   printf("  --help              Show this help\n");
 }
 
-int main(int argc, char *argv[]) {
+int main(int argc, char* argv[]) {
   bool use_tls = false;
-  char *tls_cert = NULL;
-  char *tls_key = NULL;
-  char *tls_ca = NULL;
+  char* tls_cert = NULL;
+  char* tls_key = NULL;
+  char* tls_ca = NULL;
   int port = 8080;
 
   signal(SIGPIPE, SIG_IGN);
@@ -161,7 +164,7 @@ int main(int argc, char *argv[]) {
     } else if (strcmp(argv[i], "--ca") == 0 && i + 1 < argc) {
       tls_ca = argv[++i];
     } else if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) {
-      char *end;
+      char* end;
       long p = strtol(argv[++i], &end, 10);
       if (*end || p <= 0 || p > 65535) {
         fprintf(stderr, "Error: invalid port '%s' (must be 1-65535)\n", argv[i]);