ProtonBridge v1.1.5-rc.1

1.1.5-rc.1 — consistent branding and consolidated documentation

• Update the README to describe ProtonBridge throughout, with current download
  names, package/activity identity, build toolchain, bisync controls and attribution.
• Update repository documentation pages, privacy text, contributor instructions
  and issue-template links to this fork. Remove upstream download/store claims.
• Consolidate the added guides, audit/roadmap files and release notes into this
  document. Historical details remain available through immutable Git history.
• Signed releases now extract their notes from the matching version section here;
  missing, empty or duplicate sections stop release validation.
• Retain the existing app identity, signing certificate, engine pin and runtime
  behaviour. This update contains documentation and release tooling changes.