Create cache directory before SQLite dump in pipeline

The dump phase writes to ~/.cache/codebase-memory-mcp/<project>.db
but the directory may not exist on fresh CI runners. Add cbm_mkdir_p()
to ensure the parent directory is created before writing. This fixes
smoke test failures where index_repository returned status "error"
because the dump phase couldn't create the database file.

Author: DeusData

src/pipeline/pipeline.c

@@ -17,6 +17,7 @@
 #include "graph_buffer/graph_buffer.h"
 #include "discover/discover.h"
 #include "foundation/platform.h"
+#include "foundation/compat_fs.h"
 #include "foundation/log.h"
 #include "foundation/hash_table.h"
 #include "foundation/compat.h"
@@ -633,6 +634,15 @@ int cbm_pipeline_run(cbm_pipeline_t *p) {
                      p->project_name);
         }
 
+        /* Ensure parent directory exists (e.g. ~/.cache/codebase-memory-mcp/) */
+        char db_dir[1024];
+        snprintf(db_dir, sizeof(db_dir), "%s", db_path);
+        char *last_slash = strrchr(db_dir, '/');
+        if (last_slash) {
+            *last_slash = '\0';
+            cbm_mkdir_p(db_dir, 0755);
+        }
+
         rc = cbm_gbuf_dump_to_sqlite(p->gbuf, db_path);
         if (rc != 0) {
             cbm_log_error("pipeline.err", "phase", "dump");