Simplify models provider documentation

[mrubens]

Summary

• add ChatGPT subscriptions to the inference provider overview
• remove the provider-specific Amazon Bedrock and ChatGPT subscription sections
• remove the Model IDs section
• streamline the Blaxel provider page by removing implementation-oriented runtime details
• remove base image, worker template, and worker base snapshot discussions across the sandbox docs while retaining user-facing snapshot and resume behavior
• clarify that resumable Docker tasks restart their retained container and workspace on the same host

Validation

• prettier --check apps/docs/compute.mdx apps/docs/environment-variables.mdx apps/docs/providers/compute/*.mdx apps/docs/models.mdx
• git diff --check

The full Mintlify check was unavailable because the docs package dependencies are not installed in this checkout.

[roomote-roomote]

No new code issues found. See task

_{Reviewed 00b44ab}