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/client/scanner.h

@@ -7,21 +7,25 @@
 #include <stdbool.h>
 
 typedef struct {
-  Queue *directories;
-  DIR *current_dir;
-  char *current_path;
+  Queue* directories;
+  DIR* current_dir;
+  char* current_path;
   bool use_metadata;
   unsigned long long chunk_size;
-  char **exclude_patterns;
+  char** exclude_patterns;
   int exclude_count;
-  char **include_patterns;
+  char** include_patterns;
   int include_count;
   unsigned long long max_size;
   unsigned long long min_size;
 } DirectoryScanner;
 
-DirectoryScanner *directory_scanner_create(char *root_directory, bool use_metadata, unsigned long long chunk_size, char **exclude_patterns, int exclude_count, char **include_patterns, int include_count, unsigned long long max_size, unsigned long long min_size);
-Chunk *directory_scanner_next(DirectoryScanner *scanner);
-void directory_scanner_destroy(DirectoryScanner *scanner);
+DirectoryScanner* directory_scanner_create(char* root_directory, bool use_metadata,
+                                           unsigned long long chunk_size, char** exclude_patterns,
+                                           int exclude_count, char** include_patterns,
+                                           int include_count, unsigned long long max_size,
+                                           unsigned long long min_size);
+Chunk* directory_scanner_next(DirectoryScanner* scanner);
+void directory_scanner_destroy(DirectoryScanner* scanner);
 
 #endif