FitCom 1.18.0 — experimental release

FitCom 1.18.0 starts the clean GPL-3.0-only source repository and migrates Windows updates to this project.

Experimental: use only with mutually trusted peers. Public-channel operations are not individually signed. An admitted malicious peer can forge another author's public messages, edits, or deletions. See SECURITY.md and docs/SECURITY-AUDIT.md before use. Wordle word-list redistribution rights remain unverified and are documented in THIRD_PARTY_NOTICES.md; inclusion does not establish a license for that data.

Windows: download FitCom-1.18.0-windows-x64.zip and keep fitcom.exe and fitcom-updater.exe together. Existing identities, settings, portable data, and legacy application-data locations are preserved. Updates from 1.17.1 retain protocol version 6. After this migration, automatic checks use the FitCom release feed, without a personal GitHub token or user account.

This release updates Quinn, rustls/webpki, trust roots, Tokio, WASAPI, and the withdrawn ChaCha20 package; bounds inline image memory and excludes unbounded GIF previews; protects newly generated private keys; and removes personal examples and build paths. The Ed25519 update trust anchor is unchanged. Update signatures are separate from Windows publisher signing and Apple notarization, which are not configured.

Validation: 571 library tests and 56 selected integration/timing tests passed. Hardware/external-service cases remain explicitly ignored. Advisory scan found zero vulnerability advisories and zero yanked versions; maintenance warnings remain visible. Dependency/license/source checks passed for Windows and Apple Silicon macOS. Real two-machine media/control tests and macOS runtime testing were not performed. Source and the single-commit history passed credential scans; final Windows binaries passed personal-home-path scans. See docs/VALIDATION.md for scope and limits.

Source: clean commit 86067cb. Source ZIP, project license, combined dependency/font notices, and security documentation accompany the release. The macOS workflow can attach a bundle separately; absence of a macOS asset means no Mac build is being offered yet.