search: email address search + address-first ranking; inline images; folder i18n; link security

Search (PG backend):
- '@' terms match address substrings (from/to/cc), so a partial email like
  "dyrektor@wfdif" resolves and narrows predictably as you type
- index each address split into parts, so a bare domain/local word ("wfdif")
  finds the address (indexed as one lexeme otherwise); dotted terms fall back to
  an address substring
- rank sender/recipient name+address matches above body/subject-only ones
  (addr_hit tier, then recency); cursor extended to keep keyset pagination correct
- scripts/reindex_address_parts.py backfills address tokens into existing rows

Inline images:
- extract attachments via a full MIME walk instead of shallow iter_attachments(),
  which missed inline images nested in mixed>related>alternative (cid: rendered
  broken); has_attachments counts only real (non-cid) attachments
- scripts/backfill_inline_attachments.py stores previously-missed inline images

Folder-name i18n (SPEC §12 M2):
- accent/punctuation-insensitive, multi-delimiter (/ \ .) special-use inference
  across ~13 languages; curated names (no substring false positives)

Link security (reading panel):
- links never navigate the message iframe: a parent-side click interceptor opens
  http/https in a new tab (noopener) and mailto in the composer (recipient
  pre-filled); all other schemes blocked

Backend 292 tests green, ruff + mypy --strict clean; frontend tsc/eslint/vitest clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01U72FZiF1W1pb8XxyWBTREA

backend/tests/indexer/test_mime.py

@@ -93,6 +93,39 @@ def test_attachment_extracted() -> None:
     assert parsed.attachments[0].payload == b"\x00\x01\x02data"
 
 
+def test_inline_image_nested_in_related_is_extracted() -> None:
+    # Real-world structure: mixed > related > alternative(text, html) + inline image.
+    # iter_attachments() misses the nested image; a full walk must find it so the
+    # cid: reference resolves (regression: broken inline image).
+    from email.mime.image import MIMEImage
+    from email.mime.multipart import MIMEMultipart
+    from email.mime.text import MIMEText
+
+    root = MIMEMultipart("mixed")
+    root["Subject"] = "newsletter"
+    root["From"] = "biuro@kipa.pl"
+    root["To"] = "me@example.com"
+    root["Message-ID"] = "<n@x.com>"
+    related = MIMEMultipart("related")
+    alt = MIMEMultipart("alternative")
+    alt.attach(MIMEText("text version", "plain"))
+    alt.attach(MIMEText('<p>Hi <img src="cid:img001"></p>', "html"))
+    related.attach(alt)
+    img = MIMEImage(b"\x89PNG\r\n\x1a\ndata", "png")
+    img.add_header("Content-ID", "<img001>")
+    img.add_header("Content-Disposition", "inline", filename="image001.png")
+    related.attach(img)
+    root.attach(related)
+
+    parsed = parse_message(root.as_bytes())
+    assert len(parsed.attachments) == 1
+    att = parsed.attachments[0]
+    assert att.content_id == "img001"
+    assert att.mime_type == "image/png"
+    # Inline-only: no attachment chip / paperclip.
+    assert parsed.has_attachments is False
+
+
 def test_missing_message_id_returns_none() -> None:
     msg = EmailMessage()
     msg["Subject"] = "no id"