Release v0.28.8

What's Changed

• fix(cli): clarify context-limit reset for uncatalogued models by @overlord-letta in #3350
• fix(skills): remove invocation args [LET-9695] by @overlord-letta in #3365
• feat(models): restore GPT-5.6 Luna ChatGPT OAuth by @overlord-letta in #3349
• fix(cron): include authoritative time in scheduled prompts [LET-9650] by @overlord-letta in #3348
• fix(slack): allow explicitly mentioned bots [LET-9711] by @overlord-letta in #3366
• feat(skills): add OAuth 2.1 support to mcp-http helper by @sarahwooders in #3368
• chore: bump version to 0.28.8 by @github-actions[bot] in #3367

Full Changelog: v0.28.7...v0.28.8