release/v0.3.1

[albert-gee]

Existing Google accounts could be trapped before consent because reconnection first tried to establish their retiring registration. This patch marks actionable authorization failures as reconnect-required and opens the selected account's localized recovery flow through the current BusyMax-managed Desktop client. Verified Google subjects must match; replacement commits atomically to the same local account. Unverifiable legacy identities retain their data and receive an explicit separate-connection path. Cached content, preferences and pending work survive failed or cancelled authorization.

Repository cleanup removes the committed contacts baseline/verification run records and session handoff details. The contacts guide retains provider, authorization, persistence, lifecycle and regression documentation. Original run records remain in an ignored local backup. Ignore rules now cover development evidence and downloaded Google Desktop JSON; the development guide explains which generated sources, fixtures, vendored dependencies, assets and shared configurations belong in Git. Its Dart constraint example also matches the committed pubspec.

The broader audit covered all 1,216 previously tracked files and 3,802 historical blob versions across the current GitHub branches. No credential leaks or committed package/build artifacts were found. Application, platform, test, dependency, asset and build-tool inputs remain byte-identical to b7fa6c6; the existing Snap was not rebuilt or relabeled. Cleanup validation passed: 26 Dart tooling tests, 61 Python tooling tests, 111 local documentation links, ignore-rule checks, input-preservation checks and git diff --check. This documentation cleanup does not complete outstanding interactive provider acceptance.