fix(ai): prioritize Groq's most stable model, stop repeating mining disclaimer (#9)

User decision after the Groq reliability fix (previous PR): prioritize
Groq's smallest/fastest model, llama-3.1-8b-instant, over gpt-oss-120b —
it's long out of preview and has historically the best free-tier
availability, at the cost of gpt-oss-120b's better Turkish/Kurdish
fluency (which is why it was chosen originally). Model order is now
llama-3.1-8b-instant -> gpt-oss-120b -> llama-3.3-70b-versatile before
the (currently uncredited) Anthropic fallback.

Also fixed a real UX complaint: asking about the Mining Simulation made
the model repeat "this isn't real mining / it's just an estimate" in
nearly every paragraph. Added an explicit instruction to state that once,
briefly, near the start of the answer, and not repeat it — verified live,
the disclaimer now appears once per response instead of several times.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pezkuwi-telegram-miniapp",
-  "version": "1.0.241",
+  "version": "1.0.242",
   "type": "module",
   "description": "Pezkuwichain Telegram Mini App - Forum, Announcements, Rewards",
   "author": "Pezkuwichain Team",