chore(boot): 移除全部中断排查诊断（int20 测试 + T/[T]/D 打印）

定时中断已确认恢复（APIC LINT0=EXTINT）。移除 int 0x20 软件触发测试与
isr32_handler 'T'、timer_handler '[T]'、isr_default 'D' 打印，回归干净
内核，定位 sti 后新出现的 #GP（疑似 int 0x20 测试触发）。

VKernel/Kernel/intr/idt.vp

@@ -201,8 +201,6 @@ def isr29_handler() -> t.CExport | t.CVoid: isrCommonhandler(29)
 def isr30_handler() -> t.CExport | t.CVoid: isrCommonhandler(30)
 def isr31_handler() -> t.CExport | t.CVoid: isrCommonhandler(31)
 def isr32_handler() -> t.CExport | t.CVoid:
-    # [DBG] 中断入口诊断：若打印 'T' 说明 IRQ0 到达 isr32（用后移除）
-    serial.puts("T")
     timer.timer_handler()
 
 def isr33_handler() -> t.CExport | t.CVoid:

VKernel/Kernel/intr/isr.s

@@ -16,9 +16,6 @@
 isr_default:
     push rax
     push rdx
-    mov dx, 0x3F8
-    mov al, 0x44          # [DBG] 'D' = 中断向量到默认处理（用后移除）
-    out dx, al
     mov al, 0x20
     out 0xA0, al
     out 0x20, al

VKernel/Kernel/main.vp

@@ -81,11 +81,6 @@ class ViperKernel:
         asm.sti()
         serial.puts("[main] sti done\n")
 
-        # [DBG] 软件触发向量 32：验证 IDT gate 是否生效（用后移除）
-        # 有 "T" → IDT 正常，问题在 PIT/PIC 硬件送达；无 "T" → IDT/lidt 问题
-        c.Asm("int 0x20", op=[t.ASM_DESCR.CLOBBER_MEMORY])
-        serial.puts("[main] int20 test done\n")
-
         timer.timer_msleep(100)
         serial.puts("[main] msleep done\n")
         rtc.rtc_init()

VKernel/Kernel/platform/pch/timer.vp

@@ -1,7 +1,6 @@
 import platform.pch.pic as pic
 import platform.pch.pit as pit
 import sched.sched as sched
-import drivers.serial.uart.serial as serial
 import asm
 import t, c
 
@@ -13,7 +12,6 @@ ticks:         t.CStatic | t.CVolatile | t.CUInt64T = 0
 seconds:       t.CStatic | t.CVolatile | t.CUInt32T = 0
 milliseconds:  t.CStatic | t.CVolatile | t.CUInt32T = 0
 timer_running: t.CStatic | t.CVolatile | bool       = False
-_dbg_last:     t.CUInt64T = 0
 
 def timer_init():
     global ticks, seconds, milliseconds, timer_running
@@ -26,7 +24,7 @@ def timer_init():
     pit.pit_init(TIMER_FREQUENCY)
 
 def timer_handler():
-    global ticks, seconds, milliseconds, timer_running, _dbg_last
+    global ticks, seconds, milliseconds, timer_running
     if not timer_running:
         pic.eoi(0)
         return
@@ -37,10 +35,6 @@ def timer_handler():
         seconds = seconds + 1
         milliseconds = milliseconds - 1000
     c.Asm("mfence", op=[t.ASM_DESCR.CLOBBER_MEMORY])
-    # [DBG] 每 250 拍打印一次，验证定时器中断是否触发（排查 sti 后挂起，用后移除）
-    if ticks - _dbg_last >= 250:
-        _dbg_last = ticks
-        serial.puts("[T]")
     sched.Scheduler.sched_tick()
     pic.eoi(0)