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>

tests/testutil.h

@@ -21,9 +21,9 @@
 #include <akgl/error.h>
 
 /** @brief Fail the enclosing ATTEMPT block unless @p cond holds. */
-#define TEST_ASSERT(e, cond, ...)					\
-    if ( ! (cond) ) {							\
-	FAIL_BREAK(e, AKGL_ERR_BEHAVIOR, __VA_ARGS__);			\
+#define TEST_ASSERT(e, cond, ...)			\
+    if ( ! (cond) ) {					\
+	FAIL_BREAK(e, AKGL_ERR_BEHAVIOR, __VA_ARGS__);	\
     }
 
 /**
@@ -33,25 +33,25 @@
  * paths in a row without draining AKERR_ARRAY_ERROR. Pass 0 for @p expected to
  * require success.
  */
-#define TEST_EXPECT_STATUS(e, expected, stmt, desc)			\
-    {									\
-	akerr_ErrorContext *__tec = (stmt);				\
-	int __tst = ( __tec == NULL ) ? 0 : __tec->status;		\
-	if ( __tec != NULL ) {						\
-	    __tec->handled = true;					\
-	    __tec = akerr_release_error(__tec);				\
-	}								\
-	if ( __tst != (expected) ) {					\
-	    FAIL_BREAK(							\
-		e,							\
-		AKGL_ERR_BEHAVIOR,					\
-		"%s: expected status %d (%s), got %d (%s)",		\
-		desc,							\
-		(int)(expected),					\
-		akerr_name_for_status((int)(expected), NULL),		\
-		__tst,							\
-		akerr_name_for_status(__tst, NULL));			\
-	}								\
+#define TEST_EXPECT_STATUS(e, expected, stmt, desc)		\
+    {								\
+	akerr_ErrorContext *__tec = (stmt);			\
+	int __tst = ( __tec == NULL ) ? 0 : __tec->status;	\
+	if ( __tec != NULL ) {					\
+	    __tec->handled = true;				\
+	    __tec = akerr_release_error(__tec);			\
+	}							\
+	if ( __tst != (expected) ) {				\
+	    FAIL_BREAK(						\
+		e,						\
+		AKGL_ERR_BEHAVIOR,				\
+		"%s: expected status %d (%s), got %d (%s)",	\
+		desc,						\
+		(int)(expected),				\
+		akerr_name_for_status((int)(expected), NULL),	\
+		__tst,						\
+		akerr_name_for_status(__tst, NULL));		\
+	}							\
     }
 
 /** @brief Require that @p stmt succeeds, reporting @p desc if it does not. */