Ghost FTP v0.91.0 — saved-site duplicate discovery

Feature release following the verified published v0.90.1 source. All existing
Windows/Linux, Android and macOS application and build paths are retained.

New Windows/Linux Site Manager feature

• Discover possible duplicate saved connections using protocol, DNS-case-insensitive
  host, port and case-sensitive username. Hostnames differing only by a
  trailing DNS dot are recognized.
• A Duplicates filter lists every affected saved profile, with a live count.
• Selecting/editing a site shows an accessible warning when its effective
  endpoint and account match another saved profile.
• Detection is deliberately advisory: profiles, bookmarks, notes and
  credentials are never merged, overwritten, deleted or exported. Separate
  aliases or accounts may legitimately point to the same server.
• Temporary/ephemeral Quick Connect entries are excluded from the inventory.
• New regression checks run real production TypeScript for identity collisions,
  case handling, incomplete records, selection exclusions, changing drafts and
  UI wiring.

Verification and limitations

Run all six required workflows against the exact latest PR SHA, then against
the merged main SHA. Only publish once the canonical release workflow verifies
the actual packages and checksums. Do not alter earlier release tags or
replace the verified README screenshots.

This is a Windows/Linux Site Manager feature, not a claim that Android
or macOS has an identical duplicate-profile view. Full 75-screen installed-app
pixel/click acceptance and macOS FTPS/SFTP identity verification remain open.