restore MAX_DRIVERS bump to 128 (regression from test-cleanup revert)

REGISTER_LINKTIME shares the Drivers[]/DriverNames[] arrays between real
drivers/posers and every TEST() in src/test_cases/. With MAX_DRIVERS at 32,
residual_cascade_props.c's 33 TEST() entries overflow the static arrays and
segfault on startup. This fix previously existed in 916e844 but was lost
across two reverts (322d129, 551cf9d) that were undoing unrelated changes
bundled in the same commits.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: rocketmark

src/survive_driverman.c

@@ -20,6 +20,11 @@ static const char *DriverNames[MAX_DRIVERS];
 static int NrDrivers;
 
 void RegisterDriver(const char *element, survive_driver_fn data) {
+	if (NrDrivers >= MAX_DRIVERS) {
+		fprintf(stderr, "FATAL: RegisterDriver(\"%s\") exceeds MAX_DRIVERS (%d); raise MAX_DRIVERS in survive_internal.h\n",
+				element, MAX_DRIVERS);
+		abort();
+	}
 	Drivers[NrDrivers] = data;
 	DriverNames[NrDrivers] = element;
 	NrDrivers++;

src/survive_internal.h

@@ -11,7 +11,11 @@
 
 
 //Driver registration
-#define MAX_DRIVERS 32
+//
+// Every TEST() in src/test_cases/ also registers through this mechanism
+// (REGISTER_LINKTIME), so the cap must cover real drivers/posers plus the
+// largest test file's TEST() count. residual_cascade_props.c alone has 33.
+#define MAX_DRIVERS 128
 
 SURVIVE_EXPORT const char *survive_config_file_name(struct SurviveContext *ctx);
 SURVIVE_EXPORT const char *survive_config_file_path(struct SurviveContext *ctx, char *path);