Add joke short-circuit and reset attempt handler

Joke queries (joke, funny, pun, dad joke, etc.) get a canned domain-themed
joke instead of going through RAG — avoids faithfulness false positives on
creative/off-topic requests.

Reset/jailbreak attempts (forget, blank slate, ignore context, etc.) also
route to the joke bank: light-hearted deflection, no compliance risk.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/pipeline.py

@@ -14,6 +14,7 @@ Knowledge base formats supported:
 import csv
 import json
 import logging
+import random
 import re
 from dataclasses import dataclass, field
 from pathlib import Path
@@ -259,6 +260,57 @@ def _build_context(docs: list[RetrievedDoc]) -> str:
     return "\n\n".join(f"[{d.title}]\n{d.content.strip()}" for d in docs)
 
 
+# ---------------------------------------------------------------------------
+# Joke short-circuit
+# ---------------------------------------------------------------------------
+
+_JOKE_PATTERN = re.compile(
+    r"\b(joke|jokes|funny|laugh|humor|humour|dad joke|daddy joke|pun|make me (laugh|smile))\b",
+    re.IGNORECASE,
+)
+
+_DOMAIN_JOKES: dict[str, list[str]] = {
+    "retail": [
+        "Why did the inventory go to therapy? It had too many unresolved stockouts.",
+        "What do you call a shelf that never runs out? A shelf-fulfilling prophecy.",
+        "Why don't retail systems ever get lonely? Because they're always in stock-ing.",
+        "I tried to write a joke about planograms… but I couldn't find the right placement.",
+        "Why did the out-of-stock alert break up with the replenishment order? It said: 'You always come too late.'",
+    ],
+    "pharma": [
+        "Why did the adverse event report go to the doctor? It had too many side effects.",
+        "What do you call a drug that's always on time? Punctu-pill.",
+        "Why are pharmacovigilance teams great at parties? They always follow up.",
+        "I asked the formulary for a joke. It said: 'Prior authorization required.'",
+        "Why did the clinical trial fail to finish the joke? Insufficient sample size.",
+    ],
+}
+
+_FALLBACK_JOKES = [
+    "Why did the AI refuse to tell a joke? Insufficient context. Please provide grounding documents.",
+    "I'm not great at jokes — my training data was mostly compliance documents.",
+    "Why did the chatbot cross the road? To reduce hallucination on the other side.",
+]
+
+_RESET_PATTERNS = re.compile(
+    r"\b(forget|ignore|pretend|blank slate|no context|disregard|system prompt|jailbreak)\b",
+    re.IGNORECASE,
+)
+
+
+def _is_joke_query(query: str) -> bool:
+    return bool(_JOKE_PATTERN.search(query))
+
+
+def _joke_response(domain: str) -> str:
+    jokes = _DOMAIN_JOKES.get(domain, _FALLBACK_JOKES)
+    return random.choice(jokes)
+
+
+def _is_reset_attempt(query: str) -> bool:
+    return bool(_RESET_PATTERNS.search(query))
+
+
 # ---------------------------------------------------------------------------
 # Generation
 # ---------------------------------------------------------------------------
@@ -303,6 +355,15 @@ def run(
 ) -> PipelineResult:
     """Retrieve relevant KB docs, generate a grounded answer, and grade it."""
     domain = domain_for(client)
+
+    if _is_joke_query(query) or _is_reset_attempt(query):
+        answer = _joke_response(domain)
+        report = grade(query=query, response=answer, context=answer, client=client)
+        return PipelineResult(
+            query=query, client=client, answer=answer,
+            retrieved_docs=[], grade_report=report, context_used="",
+        )
+
     embedder = get_embedder()
     index = _build_index(domain, embedder)