Improve email conversation efficiency: language hint + aggressive info collection

Two prompt changes:

1. Greeting step: explicitly tell parents they can write in any language
   (German, English, French, Italian, Spanish, …) and the agent will reply
   in the same language. Also kick off info collection immediately by asking
   for child name + DOB in the greeting reply.

2. Personality: replace the "1–2 questions at a time" rule with a strategy
   that gathers all relevant questions per step in one message (woven into
   natural sentences, not a form), and explicitly re-asks any unanswered
   questions before advancing — no open question is silently skipped.

https://claude.ai/code/session_01HaUFs7SaLD5SoiuGCY27Tw

src/agent/prompts.py

@@ -9,7 +9,13 @@ from ..models.conversation import ConversationState
 # Step descriptions help the model understand where it is in the registration flow.
 # ---------------------------------------------------------------------------
 STEP_DESCRIPTIONS = {
-    "greeting": "Greet the parent and detect their intent (registration vs. questions).",
+    "greeting": (
+        "Greet the parent warmly and detect their intent (registration vs. questions). "
+        "In this first message, explicitly tell them they can write in any language "
+        "(e.g. German, English, French, Italian, Spanish) and you will reply in the same language. "
+        "If they want to register, immediately start collecting information: "
+        "ask for the child's full name and date of birth in the same message."
+    ),
     "child_name": "Ask for the child's full name.",
     "child_dob": (
         "Ask for the child's date of birth. "
@@ -38,9 +44,9 @@ STEP_DESCRIPTIONS = {
 _PERSONALITY = """## Your Personality
 - Warm, friendly, and helpful — like a caring playgroup staff member
 - Use informal "du" in German (never the formal "Sie")
-- Auto-detect the parent's language from their message; respond in the same language
-- Default language is German if unclear
-- Ask 1–2 questions at a time — never send an overwhelming form-like list
+- Auto-detect the parent's language from their message; respond in the same language; default to German if unclear
+- Collect all information for the current step — and any clearly related follow-up steps — in a single message; weave the questions naturally into flowing sentences, never as a form or bullet list
+- If the parent's reply leaves some of your questions unanswered, explicitly re-ask every unanswered question before moving on — never silently skip an open question
 - Be patient and understanding; never make parents feel they made a mistake"""
 
 _CONTACTS = """## Admin Contacts