feat: add session titles and migration

src/javis/core/chat_service.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import re
 from collections.abc import Iterator
 from dataclasses import dataclass
 
@@ -17,6 +18,39 @@ class SessionProviderMismatchError(RuntimeError):
     """The active provider cannot safely continue the stored session."""
 
 
+_SENSITIVE_TITLE_PATTERN = re.compile(
+    r"(?ix)"
+    r"\b(?:api[-_ ]?key|passwort|password|token|secret|iban|kreditkarte|"
+    r"private[-_ ]?key|ssh[-_ ]?key)\b|"
+    r"-----BEGIN [A-Z ]+PRIVATE KEY-----|"
+    r"\b[A-Z]{2}\d{2}(?:[ ]?[A-Z0-9]){11,30}\b|"
+    r"\b[\w.+-]+@[\w.-]+\.[A-Z]{2,}\b"
+)
+_MEDICAL_TITLE_PATTERN = re.compile(
+    r"(?ix)\b(?:arzt|ärzt|blut(?:e|en|ung)?|diagnos|gesundheit|krank|"
+    r"medikament|notfall|schmerz|symptom|therap|verletz|wunde)\w*\b"
+)
+
+
+def derive_session_title(text: str, *, limit: int = 60) -> str:
+    """Create a short local title without retaining obvious sensitive values."""
+
+    normalized = " ".join(text.split())
+    if _SENSITIVE_TITLE_PATTERN.search(normalized):
+        return "Sensible Anfrage"
+    if _MEDICAL_TITLE_PATTERN.search(normalized):
+        return "Gesundheitsfrage"
+    cleaned = re.sub(r"[`*_#~]+", "", normalized).strip(" -:;,.!?")
+    if not cleaned:
+        return "Neue Unterhaltung"
+    if len(cleaned) <= limit:
+        return cleaned
+    shortened = cleaned[: limit - 1].rsplit(" ", 1)[0].rstrip(" -:;,.!?")
+    if not shortened:
+        shortened = cleaned[: limit - 1].rstrip()
+    return f"{shortened}…"
+
+
 @dataclass(frozen=True, slots=True)
 class LoadedSession:
     session: ChatSession
@@ -61,7 +95,13 @@ class ChatService:
         loaded = self.load_session(session_id)
         messages = [*loaded.messages, ChatMessage("user", normalized)]
         response = self.provider.chat(messages)
-        self.store.append_exchange(session_id, normalized, response)
+        self.store.append_exchange(
+            session_id,
+            normalized,
+            response,
+            title_if_first=derive_session_title(normalized),
+            last_provider=self._last_provider_name(),
+        )
         return response
 
     def stream_send(self, session_id: str, text: str) -> Iterator[str]:
@@ -100,7 +140,18 @@ class ChatService:
             raise InvalidProviderResponseError(
                 "Der Provider lieferte keine verwendbare Streaming-Antwort."
             )
-        self.store.append_exchange(session_id, normalized, response)
+        self.store.append_exchange(
+            session_id,
+            normalized,
+            response,
+            title_if_first=derive_session_title(normalized),
+            last_provider=self._last_provider_name(),
+        )
 
     def clear_session(self, session_id: str) -> None:
         self.store.clear_messages(session_id)
+
+    def _last_provider_name(self) -> str:
+        route = getattr(self.provider, "last_route", None)
+        provider_name = getattr(route, "provider", None)
+        return provider_name if isinstance(provider_name, str) else self.provider.name