aither-v0.6.0

Added

• add aither-codex provider and gate local web tools on hosted capabilities
• [breaking] tools report progress during a call; aither-mcp forwards it as notifications/progress (#79)

Other

• Merge branch 'main' into dev
• clippy nits
• fmt
• bump zenwave to 0.7 and register aither-codex for release
• Merge remote-tracking branch 'origin/dev' into codex-provider