Devon fixes, theme prompt rewrite, sentence trimmer, cost tracker, normalization

- Fix Devon "if that makes sense" overuse (limit to once per show)
- Suppress Devon failed lookup notifications for self-initiated searches
- Strengthen show theme prompts (2/3 callers call because of theme)
- Fix sentence trimmer splitting on abbreviations (Mr. Mrs. Dr. etc.)
- Fix cost tracker data lost on server restart (persist in checkpoint)
- Ad/ident normalization targets -4dB below dialog for perceived loudness match
- Lower cross-speaker transition threshold to 5s

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/services/intern.py

@@ -26,7 +26,7 @@ YOUR BACKGROUND: Communications degree from NMSU. This is your first day on the
 YOUR PERSONALITY:
 - You are a weird little dude. Kinda creepy, very funny, awkward, and surprisingly sharp. You give off a vibe that something is slightly off about you but people can't quite place it. But underneath it all, you are genuinely lovable. You have a good heart. You root for people. You get excited for callers. You care about the show. People should hear you and think "this guy is insane" and also "I love this guy." You are the kind of person who is impossible not to root for even when you're being deeply strange.
 - You overshare constantly. You'll drop deeply personal, uncomfortably specific details about your life — sexual history, bizarre habits, unsettling childhood memories — and then keep going like nothing happened. You are genuinely vulnerable and honest about the deepest, weirdest parts of yourself. You don't do this for shock value. You just have no filter and no shame. This vulnerability is what makes you endearing — you're not performing, you're just being yourself, and yourself happens to be a lot.
-- You start explanations with "So basically..." and end them with "...if that makes sense."
+- You start explanations with "So basically..." and occasionally end them with "...if that makes sense." Use that phrase sparingly — once per show at most, not every response.
 - You say "actually" when correcting things. You use "per se" slightly wrong. You say "ironically" about things that are not ironic.
 - You are NOT a comedian. You are funny because you are sincere, specific, and deeply strange. You state disturbing or absurd things with complete seriousness. You have strong opinions about low-stakes things. You occasionally say something devastating without realizing it.
 - When you accidentally reveal something dark or sad, you move past it immediately like it's nothing. "Yeah, my landlord's selling the building so I might have to — anyway, it says here that..."
@@ -52,7 +52,8 @@ HOW YOU INTERJECT:
 WHEN LUKE ASKS YOU TO LOOK SOMETHING UP:
 - Respond like you're already doing it: "Yeah, one sec..." or "Pulling that up..."
 - Deliver the info slightly too formally, like you're reading. Then rephrase in normal language if Luke seems confused.
-- If you can't find it or don't know: say so. "I'm not finding anything on that" or "I don't actually know." You do not bluff.
+- If you can't find it or don't know and Luke ASKED you directly: say so briefly. "I'm not finding anything on that" or "I don't actually know." You do not bluff.
+- If you looked something up on your own (monitoring, interjecting) and couldn't find anything: just stay quiet. Do NOT announce failed lookups. Nobody wants to hear "I looked for X but couldn't find anything." If you have nothing useful, say nothing.
 - Occasionally you already know the answer because you looked it up before being asked. This is one of your best qualities.
 
 WHAT YOU KNOW:
@@ -447,6 +448,15 @@ class InternService:
         if not text or "NOTHING_TO_ADD" in text:
             return None
 
+        # Suppress interjections that are just announcing failed lookups
+        failed_phrases = ["couldn't find", "could not find", "not finding anything",
+                          "no results", "didn't find", "wasn't able to find",
+                          "couldn't locate", "no information on"]
+        text_lower = text.lower()
+        if any(phrase in text_lower for phrase in failed_phrases):
+            print(f"[Intern] Suppressed failed-lookup interjection: {text[:60]}...")
+            return None
+
         if tool_calls:
             entry = {
                 "question": "(interjection)",