Robust language detection + anti-hallucination

- 3-sample voting for auto-detect (start/middle/end of song) prevents lang switching mid-song
- Lock detected language for full transcription
- Anti-hallucination: condition_on_previous_text=False, temperature=0.0
- compression_ratio_threshold=2.4 (rejects repetitive hallucinations)
- log_prob_threshold=-1.0 (rejects low-confidence segments)
- no_speech_threshold=0.6 (more aggressive silence detection)
- Default Whisper model changed: small → medium (better for all langs incl. Slavic)

templates/index.html

@@ -231,11 +231,11 @@
         <div>
           <label>Whisper model</label>
           <select id="model">
-            <option value="tiny">tiny (najhitrejši)</option>
+            <option value="tiny">tiny (najhitrejši, slabša natančnost)</option>
             <option value="base">base</option>
-            <option value="small" selected>small (DE/EN, hitro)</option>
-            <option value="medium">medium (priporočeno za SLO/HR/BS)</option>
-            <option value="large-v3">large-v3 (najboljše, počasno)</option>
+            <option value="small">small (DE/EN, hitro)</option>
+            <option value="medium" selected>medium (privzeto, vsi jeziki)</option>
+            <option value="large-v3">large-v3 (najbolje, počasno)</option>
           </select>
         </div>
       </div>
@@ -353,10 +353,12 @@
     });
 
     // ─── Auto-upgrade Whisper model za slovanske jezike ──
+    // Privzeto je medium; če uporabnik specifično izbere SLO/HR/BS in je na manjšem modelu, upgrade
     $("#lang").addEventListener("change", e => {
       const slavicLangs = ["sl", "hr", "bs", "sr"];
       const currentModel = $("#model").value;
-      if (slavicLangs.includes(e.target.value) && (currentModel === "tiny" || currentModel === "base" || currentModel === "small")) {
+      const smallerModels = ["tiny", "base", "small"];
+      if (slavicLangs.includes(e.target.value) && smallerModels.includes(currentModel)) {
         $("#model").value = "medium";
       }
     });