feat: upgrade MiniMax provider to M2.7 with correct API base URL

[octo-patch]

Summary

Upgrade MiniMax provider configuration from the outdated M2.5 + api.minimax.chat to the current M2.7 + api.minimax.io.

Changes

• Base URL: Updated from https://api.minimax.chat/v1 to https://api.minimax.io/v1 (the current official API domain)
• Models: Replaced MiniMax-M2.5 with MiniMax-M2.7 and added MiniMax-M2.7-highspeed (204K context window)
• URL matcher: Added api.minimax.io to the hosts array so auto-detection works for both old and new domains
• README (EN + ZH): Fixed the MiniMax row — corrected base URL, model name, and platform link
• Docs: Updated docs/common-provider-setups.md with current info
• Tests: Added 3 unit tests for MiniMax URL detection (new domain, legacy domain, subdomain)

Files changed (7)

File	Change
src/shared/api-provider-guidance.ts	Updated base URL, model, and hosts matcher
src/shared/api-model-presets.ts	M2.5 → M2.7 + M2.7-highspeed in custom presets
docs/common-provider-setups.md	Updated MiniMax row
readme.md	Fixed MiniMax entry in Quick Start table
README_zh.md	Fixed MiniMax entry in Quick Start table
tests/provider-guidance.test.ts	Added 3 MiniMax detection tests
tests/api-config-state.test.ts	Updated preset assertion for new model IDs

Test plan

• npx vitest run tests/provider-guidance.test.ts — all 10 tests pass (including 3 new MiniMax tests)
• npx vitest run tests/api-config-state.test.ts — all 15 tests pass
• Full test suite: all pre-existing failures are unrelated (timeout issues in store-encryption, remote-manager, etc.)
• Manual: verify detectCommonProviderSetup('https://api.minimax.io/v1') returns the MiniMax setup in the UI

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Context: MiniMax migrated their API from api.minimax.chat to api.minimax.io, and released M2.7 as their latest flagship model (204K context). This PR ensures Open Cowork users get the correct setup guidance.