v0.7.0-preview

Verification boundaries

Release artifacts are published only after the repository quality gates and the
platform package jobs complete. The uploaded package-smoke evidence covers the
bundle layout, packaged backend health and authentication, and a minimal launch
of a platform-specific target. On macOS, the launch target is the executable
inside the generated .app bundle. On Windows, the launch target is the
release-build executable at src-tauri/target/release/geochat-desktop-tauri.exe;
it is not an executable discovered through an NSIS or MSI installation.

That evidence does not claim any of the following unless a later release
explicitly says otherwise:

• Developer ID, Authenticode, Apple notarization, or staple verification;
• successful requests to a live third-party model provider;
• successful installation of the Windows NSIS or MSI artifact, or a
  post-install launch from either installer;
• production service deployment or remote environment acceptance;
• exhaustive visual, keyboard, screen-reader, or reduced-motion acceptance;
• feature-level end-to-end behavior from the packaged UI beyond the documented
  launch smoke.

The deterministic desktop conversation/canvas scenario is a debug-only local
acceptance test. It is intentionally reported separately from packaged-release
evidence.

Full Changelog: v0.6.1...v0.7.0-preview