Add tools.cron.command_allowed_remotes so remote channels can be
explicitly allowlisted for command-executing cron jobs. Entries support
channel names, channel:chat_id pairs, and a literal * to allow every
non-empty channel while preserving the default deny posture.
The existing allow_command and command_confirm checks still apply after the
channel gate. Update tests, config examples, and cron documentation for the
new option.
* add gemini web search provider
* fix(web): prefer free providers before Gemini in auto mode
* fix(web): expose gemini api key and model settings
* fix(web): prefer configured providers before Gemini in auto mode
* fix(web): satisfy gemini lint checks
* fix(web): address gemini provider review feedback
* test(web): align auto-provider expectations
* fix(web): let gemini ignore search range
