fix: correct DSN dice skins + UI tweaks (v1.3.9)

- DSN: register ze-stress-dice system separately so normal/stress d6 presets dont overwrite each other
- DSN: use term.options.appearance.system to force correct preset on every roll - bypasses user saved DSN system preference
- Remove v1.3.8 flag-patching ready hook (no longer needed)
- UI: dice icon on attribute header enlarged (13px to 20px) with glow
- UI: attr-btn smaller (24px to 16px), skill +/- smaller (20px to 14px)
- UI: clicking attribute name, skill name, or weapon name now triggers roll

system.json

@@ -2,7 +2,7 @@
   "id": "zero-engine",
   "title": "Zero Engine (SLA Industries)",
   "description": "A basic game system for SLA Industries using the Zero Engine rules.",
-  "version": "1.3.8",
+  "version": "1.3.9",
   "compatibility": {
     "minimum": 13,
     "verified": "14.359"