feat: D4 DKM colored log prefixes - every driver has its own temper

- log.c: color context (log_set_color / log_color_enable); ANSI only goes to serial, BOOTLOG.TXT buffer stays clean plain text
- kernel_api.c: dkm_log_set_driver() — driver-name FNV-1a hash into an 8-color bright ANSI palette, deterministic per driver
- load sites (dkm_core builtin + boot_modules external) set color around driver_init and clear after
- FUCK [debug] color_log gate (dev=1, release=0)
- QEMU verified: 1150 colored lines, per-driver stable colors (.build_tmp/qemu_serial_d4color.log)

CODE/UTSM/include/utsm/dkm.h

@@ -158,6 +158,8 @@ typedef struct dkm_builtin_driver {
 } dkm_builtin_driver;
 
 void dkm_init(void);
+/* D4: 设置当前驱动日志颜色上下文（driver_init 前设置，返回后清 0） */
+void dkm_log_set_driver(const char *name);
 int dkm_load_builtin(const dkm_builtin_driver *driver);
 void dkm_scan_boot_modules(void);
 void dsm_load_by_manifest(void);