fix: address PR review — doc accuracy, clang-tidy info, config leak fix

Review findings addressed:

Critical:
- cmake-expert.md: replace commented-out sanitizer lines with actual
  SANITIZER cache variable block, fix ENABLE_ASAN/TSAN/UBSAN pattern
- integrator.md: update YAML example to v7, use -DSANITIZER= instead
  of raw flags, add symlink + LSAN suppression steps

Warnings:
- ci.yaml: rename clang-tidy step to 'informational, non-blocking',
  add ::warning:: workflow command for visibility
- client_cli.c: add goto cleanup pattern to free config on error paths
  (skip for multithreaded path where pipeline_context_sender_destroy
  already owns config)

Suggestions:
- test-writer.md: clarify conftest.py is at tests/conftest.py
- .lsan-suppressions.txt: remove config_create suppression (leak fixed)

src/client/client_cli.c

@@ -74,6 +74,7 @@ int main(int argc, char* argv[]) {
   Config* config = config_create(str_dup(PROTOCOL_VERSION), NULL, NULL, save_to_disk, false, false,
                                  false, false, 5, false, 0);
   int exit_code = 0;
+  bool config_owned_by_pipeline = false;
 
   int positional_args[2];
   int positional_count = 0;
@@ -291,12 +292,15 @@ int main(int argc, char* argv[]) {
     tls_global_init();
   }
 
-  if (config->use_multithreading)
+  if (config->use_multithreading) {
+    config_owned_by_pipeline = true;
     exit_code = send_files_multithreaded(config);
-  else
+  } else {
     exit_code = send_files(config);
+  }
 
 cleanup:
-  config_delete(config);
+  if (!config_owned_by_pipeline)
+    config_delete(config);
   return exit_code;
 }