perf(mail): Roh-Byte-Vorfilter in search_mail -- grep-Tempo ueber grosse Maildirs

Nur Mails voll parsen, deren Rohtext den Suchbegriff enthaelt. Suche ueber
~13k Mails jetzt ~17s statt >120s (Deadline) und findet auch grosse Ordner (Trash).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XhHNJKk3RsHgUsJ27WQSom

mail/server.py

@@ -248,12 +248,30 @@ def search_mail(
             md = _open_folder(acct_path, fld)
             if not md:
                 continue
-            for key, msg in _iter_messages(md):
+            qbytes = query_lower.encode("utf-8", "ignore")
+            try:
+                keys = list(md.keys())
+            except Exception:
+                keys = []
+            for key in keys:
+                if time.monotonic() - t0 > DEADLINE_S:
+                    truncated = True
+                    break
+                # Schneller Roh-Byte-Vorfilter: nur Mails voll parsen, die den
+                # Suchbegriff im Rohtext enthalten (grep-Tempo statt 13k Voll-Parses).
                 try:
+                    raw = md.get_bytes(key)
+                except Exception:
+                    continue
+                if qbytes not in raw.lower():
+                    continue
+                try:
+                    msg = md.get_message(key)
                     subj = _decode_hdr(msg.get("Subject", ""))
                     frm = _decode_hdr(msg.get("From", ""))
                     to = _decode_hdr(msg.get("To", ""))
                     date_str = msg.get("Date", "")
+                    # Bestaetigen ueber dekodierte Header ODER Body (Roh-Treffer verifizieren)
                     if query_lower not in f"{subj} {frm} {to}".lower():
                         if query_lower not in _get_body(msg).lower():
                             continue
@@ -263,9 +281,6 @@ def search_mail(
                 if len(matches) >= MAX_SCAN:
                     truncated = True
                     break
-                if time.monotonic() - t0 > DEADLINE_S:
-                    truncated = True
-                    break
             if truncated:
                 break
         if truncated: