fix(vkernel): 键盘无法输入 - 键盘/鼠标共享 0x60 统一为单一消费者(IRQ1 ISR→buffer→desktop 轮询)，IRQ1 只收键盘字节

VKernel/Kernel/drivers/input/keyboard/keyboard.vp

@@ -64,6 +64,11 @@ def _wait_write():
 def irq_handler() -> int:
     global buf_head, buf_tail, buf_count, kbd_irq_cnt
     kbd_irq_cnt += 1
+    # 0x60 是键盘/鼠标**共享**的输出缓冲：AUX 位（0x64 bit5）置位表示这是鼠标字节，
+    # 不属于键盘 —— 直接读走会让鼠标驱动永远拿不到（本 ISR 只收键盘字节）。
+    st: uint8 = asm.inb(KBD_STATUS)
+    if (st & 0x20) != 0:
+        return 0
     scancode: uint8 = asm.inb(KBD_DATA)
     if buf_count < KBD_BUF_SIZE:
         buffer[buf_tail] = scancode

VKernel/Kernel/services/desktop.vp

@@ -739,7 +739,9 @@ def _update_keyboard():
     global _ps2_e0_pending
     # Quick check: skip if no PS/2 data and no USB data
     ps2_status: uint8 = asm.inb(0x64)
-    if (ps2_status & 0x01) == 0 and not usb_kbd.has_data():
+    # keyboard 的缓冲也要算"有数据"：键盘字节是由 IRQ1 收进 buffer 的，
+    # 此时 0x64 bit0 往往已被 ISR 读空，若只看 0x64 就会漏掉整批按键。
+    if (ps2_status & 0x01) == 0 and not usb_kbd.has_data() and keyboard.has_data() == 0:
         _check_key_repeat()
         return
     if _kbd_irq_masked == 0:
@@ -788,17 +790,23 @@ def _update_keyboard():
                 rel_evt._pad1 = 0
                 rel_evt._pad2 = 0
                 _push_event(rel_evt)
+    # AUX（鼠标）字节：本层只负责丢弃。键盘字节**绝不在这里 inb(0x60)** ——
+    # 0x60 是键盘/鼠标共享的输出缓冲，IRQ1 ISR 已把键盘字节收进 keyboard 缓冲，
+    # 这里再读一次会把 ISR 的字节抢走（现场：ki=2，键盘完全无法输入）。
     ps2_poll_count: int = 0
     while ps2_poll_count < 16:
         ps2_status: uint8 = asm.inb(0x64)
         if (ps2_status & 0x01) == 0:
             break
-        if (ps2_status & 0x20) != 0:
-            asm.inb(0x60)
-            ps2_poll_count += 1
-            continue
-        sc: uint8 = asm.inb(0x60)
+        if (ps2_status & 0x20) == 0:
+            break
+        asm.inb(0x60)
         ps2_poll_count += 1
+    # 键盘扫描码的唯一消费者：keyboard 驱动缓冲（IRQ1 → buffer → 这里取）
+    kbd_scan_cnt: int = 0
+    while keyboard.has_data() and kbd_scan_cnt < 16:
+        sc: uint8 = keyboard.read_scancode()
+        kbd_scan_cnt += 1
         if sc == 0x00 or sc == 0xFA or sc == 0xFE or sc == 0xFF:
             _ps2_e0_pending = 0
             continue