feat(gui): Upgrade to high-res 800x600, sharp 8x16 font, IRQ12 PS/2 mouse driver, and polished window manager

- Upgrade resolution to 800x600 @ 32bpp TrueColor with Bochs/QEMU VBE LFB
- Implement full 8042 Aux PS/2 mouse controller driver on IRQ 12 (vector 44) with packet decode and bounds clamping
- Add high-definition 8x16 font rasterizer with text drop shadows for sharp typography
- Upgrade to smooth 16x24 anti-aliased cursor with dark slate outline and drop shadow
- Increase titlebars to 24px and taskbar to 32px with modern desktop styling
- Re-architect applications (SysMon, Terminal, Explorer, Calc, Paint, About) for spacious high-res display

drivers/input/mouse.c

@@ -1,15 +1,157 @@
+// PS/2 Mouse Controller & Interrupt Driver for SUB-OS
 #include <drivers/mouse.h>
 #include <arch/x86_64/io.h>
+#include <arch/x86_64/isr.h>
+#include <arch/x86_64/pic.h>
 #include <kernel/printk.h>
 
-static mouse_state_t mouse_state = {0, 0, false, false, false};
-static int mouse_bounds_x = 80;
-static int mouse_bounds_y = 25;
+#define MOUSE_PORT_DATA   0x60
+#define MOUSE_PORT_STATUS 0x64
+#define MOUSE_PORT_CMD    0x64
+
+#define MOUSE_CMD_ENABLE_AUX   0xA8
+#define MOUSE_CMD_GET_BYTE     0x20
+#define MOUSE_CMD_SET_BYTE     0x60
+#define MOUSE_CMD_WRITE_AUX    0xD4
+
+#define MOUSE_CMD_SET_DEFAULTS 0xF6
+#define MOUSE_CMD_ENABLE_DATA  0xF4
+#define MOUSE_CMD_SET_SAMPLE   0xF3
+
+static mouse_state_t mouse_state = {400, 300, false, false, false};
+static int mouse_bounds_x = 800;
+static int mouse_bounds_y = 600;
+
+static uint8_t mouse_cycle = 0;
+static uint8_t mouse_packet[3];
+
+static inline void mouse_wait_write(void) {
+    uint32_t timeout = 100000;
+    while ((inb(MOUSE_PORT_STATUS) & 0x02) && timeout--) {
+        io_wait();
+    }
+}
+
+static inline void mouse_wait_read(void) {
+    uint32_t timeout = 100000;
+    while (!(inb(MOUSE_PORT_STATUS) & 0x01) && timeout--) {
+        io_wait();
+    }
+}
+
+static void mouse_write_cmd(uint8_t cmd) {
+    mouse_wait_write();
+    outb(MOUSE_PORT_CMD, cmd);
+}
+
+static void mouse_write_data(uint8_t data) {
+    mouse_wait_write();
+    outb(MOUSE_PORT_CMD, MOUSE_CMD_WRITE_AUX);
+    mouse_wait_write();
+    outb(MOUSE_PORT_DATA, data);
+}
+
+static uint8_t mouse_read_data(void) {
+    mouse_wait_read();
+    return inb(MOUSE_PORT_DATA);
+}
+
+static void mouse_interrupt_handler(registers_t* regs) {
+    (void)regs;
+    uint8_t status = inb(MOUSE_PORT_STATUS);
+    if (!(status & 0x20)) {
+        // Not mouse data
+        return;
+    }
+
+    uint8_t data = inb(MOUSE_PORT_DATA);
+
+    switch (mouse_cycle) {
+        case 0:
+            // Byte 0 must have bit 3 set to 1 in standard PS/2 packet
+            if ((data & 0x08) == 0x08) {
+                mouse_packet[0] = data;
+                mouse_cycle = 1;
+            }
+            break;
+        case 1:
+            mouse_packet[1] = data;
+            mouse_cycle = 2;
+            break;
+        case 2:
+            mouse_packet[2] = data;
+            mouse_cycle = 0;
+
+            // Process Packet
+            uint8_t flags = mouse_packet[0];
+            int32_t dx = (int32_t)mouse_packet[1];
+            int32_t dy = (int32_t)mouse_packet[2];
+
+            // Sign extension
+            if (flags & 0x10) dx |= 0xFFFFFF00;
+            if (flags & 0x20) dy |= 0xFFFFFF00;
+
+            // Check overflow
+            if (flags & 0xC0) {
+                // Discard invalid/overflow packet
+                break;
+            }
+
+            // Update Coordinates (PS/2 Y delta is inverted)
+            mouse_state.x += dx;
+            mouse_state.y -= dy;
+
+            // Clamp coordinates to screen bounds
+            if (mouse_state.x < 0) mouse_state.x = 0;
+            if (mouse_state.y < 0) mouse_state.y = 0;
+            if (mouse_state.x >= mouse_bounds_x) mouse_state.x = mouse_bounds_x - 1;
+            if (mouse_state.y >= mouse_bounds_y) mouse_state.y = mouse_bounds_y - 1;
+
+            // Update button states
+            mouse_state.left_btn = (flags & 0x01) != 0;
+            mouse_state.right_btn = (flags & 0x02) != 0;
+            mouse_state.middle_btn = (flags & 0x04) != 0;
+            break;
+    }
+}
 
 void mouse_init(void) {
+#if defined(__x86_64__)
+    // 1. Enable Auxiliary Device
+    mouse_write_cmd(MOUSE_CMD_ENABLE_AUX);
+
+    // 2. Read Controller Command Byte
+    mouse_write_cmd(MOUSE_CMD_GET_BYTE);
+    uint8_t status = mouse_read_data();
+
+    // 3. Enable IRQ12 (Bit 1) & Enable Mouse Clock (Clear Bit 5)
+    status |= 0x02;
+    status &= ~0x20;
+    mouse_write_cmd(MOUSE_CMD_SET_BYTE);
+    mouse_wait_write();
+    outb(MOUSE_PORT_DATA, status);
+
+    // 4. Set Defaults & Enable Streaming
+    mouse_write_data(MOUSE_CMD_SET_DEFAULTS);
+    mouse_read_data(); // ACK (0xFA)
+
+    mouse_write_data(MOUSE_CMD_ENABLE_DATA);
+    mouse_read_data(); // ACK (0xFA)
+
+    // 5. Register IRQ 12 Handler (Vector 44 = 32 + 12)
+    isr_register_handler(44, mouse_interrupt_handler);
+
+    // 6. Unmask PIC IRQ 12
+    pic_clear_mask(12);
+#endif
+
     mouse_state.x = mouse_bounds_x / 2;
     mouse_state.y = mouse_bounds_y / 2;
-    printk(KERN_INFO "MOUSE: PS/2 Mouse Controller initialized (Bounds: %dx%d)\n",
+    mouse_state.left_btn = false;
+    mouse_state.right_btn = false;
+    mouse_state.middle_btn = false;
+
+    printk(KERN_INFO "MOUSE: PS/2 Mouse Controller initialized (IRQ 12, Bounds: %dx%d)\n",
            mouse_bounds_x, mouse_bounds_y);
 }
 
@@ -18,6 +160,8 @@ const mouse_state_t* mouse_get_state(void) {
 }
 
 void mouse_set_bounds(int max_x, int max_y) {
-    mouse_bounds_x = max_x;
-    mouse_bounds_y = max_y;
+    mouse_bounds_x = (max_x > 0) ? max_x : 800;
+    mouse_bounds_y = (max_y > 0) ? max_y : 600;
+    if (mouse_state.x >= mouse_bounds_x) mouse_state.x = mouse_bounds_x / 2;
+    if (mouse_state.y >= mouse_bounds_y) mouse_state.y = mouse_bounds_y / 2;
 }