feature: mirror all diagnostics to syslog, add VESA fallback for gfxd crashes

- syslogDump now outputs all five diagnostic sections (Fault Info,
  CPU Registers, Process Info, System Info, Call Stack) to serial,
  matching the on-screen BSOD content
- panic() detects if the crash occurred in the gfxd process and
  falls back to rendering the BSOD directly to the VESA framebuffer
  via driver.video text drawing, bypassing LVGL entirely
- Add DrawChar, DrawString, DrawHex, DrawInt to driver.video for
  8x16 bitmap font rendering directly to the framebuffer
- Export SHOULD_CRASH flag from svc.gfxd interface so test commands
  can trigger a deliberate gfxd crash
- Add app.divzero with DIV0, PF, and CRASHGFXD test commands
- Update doc/src/core/core.panic.md and doc/src/driver/video/driver.video.md

src/svc/svc.gfxd.pas

@@ -13,6 +13,10 @@ unit svc.gfxd;
 
 interface
 
+var
+    SHOULD_CRASH : boolean;  { set to true to intentionally trigger a crash for testing purposes }
+    
+
 procedure init;
 
 implementation
@@ -56,6 +60,12 @@ begin
             lvgl_handler;
             driver.video.Flush;
         end;
+        if SHOULD_CRASH then begin
+            asm
+                XOR EAX, EAX
+                DIV EAX  { this will trigger a divide by zero exception (interrupt 0) }
+            end;
+        end;
     end;
 end;