Reindent all C sources to the canonical stroustrup style

Mechanical whitespace-only change across src/, include/, tests/, and
util/, applied with scripts/reindent.sh. No behavioral change.

Most files already conformed. The genuine outliers indented at 2 columns
(json_helpers.c, util.c from akgl_rectangle_points onward, assets.c,
staticstring.c, akgl_actor_add_child, util.h, staticstring.h) or used
spaces where the canonical form is a tab (draw.c). cc-mode also re-aligns
line-continuation backslashes in multi-line macros to its default
c-backslash-column, which is required for the tree to be a fixed point of
the indenter.

Verified whitespace-only: `git diff -w` over this change is empty apart
from three trailing blank lines removed at EOF in src/heap.c,
src/registry.c, and tests/tilemap.c. The build produces no new errors and
ctest is unchanged at 13/14, with `character` still the one intentional
failure.

The tree is now a fixed point of `scripts/reindent.sh --check`.

include/akgl/SDL_GameControllerDB.h is generated and excluded.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/registry.c

@@ -95,7 +95,7 @@ akerr_ErrorContext *akgl_registry_init_actor_state_strings()
 
 akerr_ErrorContext *akgl_registry_init_sprite()
 {
-     PREPARE_ERROR(errctx);
+    PREPARE_ERROR(errctx);
     AKGL_REGISTRY_SPRITE = SDL_CreateProperties();
     FAIL_ZERO_RETURN(errctx, AKGL_REGISTRY_SPRITE, AKERR_NULLPOINTER, "Error initializing sprite registry");
     SUCCEED_RETURN(errctx);
@@ -123,7 +123,7 @@ akerr_ErrorContext AKERR_NOIGNORE *akgl_registry_load_properties(char *fname)
     json_t *props = NULL;
     const char *pkey = NULL;
     json_t *pvalue = NULL;
-    
+
     json_error_t error;
     akgl_String *tmpstr;
 
@@ -189,4 +189,3 @@ akerr_ErrorContext AKERR_NOIGNORE *akgl_get_property(char *name, akgl_String **d
     } FINISH(e, true);
     SUCCEED_RETURN(e);
 }
-