feat: secure notes + password history + custom fields + quick-win bundle

Big feature trio
- Secure notes (kind='login'|'note') reusing the encrypted_password+iv
  pipeline for the body. New sidebar entry, slideover variant (title +
  multiline body), distinct card / table-view rendering, badge in name
  column, copy-content button replacing the password copy on note rows.
- Password history: entries_password_history table keeps up to 20 prior
  ciphertexts per entry. HandleUpdateEntry pushes the pre-update
  encrypted_password into history ONLY when it actually differs from
  the incoming one (JS reuses originalEncrypted bit-for-bit when the
  plaintext is unchanged — avoids spamming history on title/folder edits).
  GET /entries/{id}/history endpoint. Slideover modal lists versions
  with mask/reveal/copy/revert. Master-pw rotation wipes history (old
  ciphertext can't be decrypted with the new key).
- Custom fields: per-entry encrypted JSON array of {label, value,
  is_secret}. Same crypto pipeline as the password. Slideover row UI
  with label/value inputs, secret toggle (eye), copy, delete. Re-
  encryption flows through bulk-import, change-master-password, and
  duplicate.

Quick wins
- Cheatsheet overlay (press '?' or topbar button or Ctrl+K). Lists all
  hotkeys + global / tray / card actions. SVG icons inline so the
  cheatsheet matches the actual app glyphs (no emoji mismatch).
- Open URL button on entry cards: ShellExecute via cmd://app/open-url,
  http(s) only, validates entry.site looks like a real hostname.
- Trash auto-purge: setting "Empty trash after N days" (never/7/30/90).
  DELETE /entries/trash/old?days=N called at every unlock.

Favicon strategy
- Subdomains (chat.deepseek.com, app.X.com…) now try the SLD first
  (deepseek.com.ico) before the full host. DDG often returns a generic
  placeholder for subdomains that passes the byte threshold; the SLD-first
  switch surfaces the real brand icon.
- Cap bumped 64 KB → 256 KB on all three sides (Delphi fetch, server
  endpoint, JS upload). DDG sometimes serves the full-res asset.

UX polish
- Click-outside-slideover: stopPropagation everywhere it bites. Custom
  fields buttons (add / delete / secret toggle / copy / eye) all stop
  the click bubble so the document-level "close on outside click" handler
  doesn't fire when rerender() detaches the target from the DOM.
- Native search-cancel button restyled: cyan accent X via mask-image,
  cursor: pointer, breathing room before the Ctrl+K kbd chip.
- Password history modal: scrollable body, multiline wrapped passwords,
  hover border highlight.
- Cheatsheet panel widened (560 → 720 px) so the descriptions no longer
  ellipsis-clip.
- "+ New" topbar splits into a small dropdown: New login / New note.
- Notes show a "note" badge in table-view name column, italic
  "Encrypted note" placeholder in the username column.

Internals
- duplicateEntry copies kind + custom_fields too (one-line forgotten
  earlier).
- entries_password_history dropped on master-pw rotation — the old
  ciphertexts are unrecoverable with the new key.
- bulk-import re-encryption path includes custom_fields.

CLAUDE.md
- "Entry payload — call sites à toucher ensemble" lists the 6 spots
  to update when adding a new (en)crypted field. Notes the historical
  miss of kind in duplicateEntry and custom_fields in the rotation +
  duplicate.

Repo hygiene
- .gitattributes forces CRLF on Delphi sources (RAD Studio refuses LF).
  text=auto for web frontend / docs, binary for .res / .exe / images.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitattributes

@@ -0,0 +1,33 @@
+# Delphi / RAD Studio source files require CRLF line endings — the IDE
+# warns ("Line endings are LF, but RAD Studio requires CRLF") and some
+# packagers refuse LF outright. Force CRLF on both checkout and check-in
+# so the working tree always has the right line endings regardless of
+# core.autocrlf setting on the dev machine.
+*.pas   text eol=crlf
+*.dpr   text eol=crlf
+*.dpk   text eol=crlf
+*.dproj text eol=crlf
+*.fmx   text eol=crlf
+*.dfm   text eol=crlf
+*.inc   text eol=crlf
+*.rc    text eol=crlf
+
+# Resource files generated from web assets — keep them binary so Git
+# doesn't try to normalise the embedded bytes.
+*.res   binary
+
+# Web frontend & docs — let Git normalise to native (LF on Linux/macOS,
+# CRLF on Windows via autocrlf). Explicit so .pas's eol=crlf doesn't
+# cascade by accident.
+*.html  text
+*.js    text
+*.css   text
+*.json  text
+*.md    text
+
+# Build outputs / archives — never normalise
+*.exe   binary
+*.dll   binary
+*.ico   binary
+*.png   binary
+*.rar   binary