Add Atlas Cloud remote starter preset

[binyangzhu000-sudo]

Summary

• add Atlas Cloud as an OpenAI-compatible remote starter preset
• default the preset to https://api.atlascloud.ai/v1 and qwen/qwen3.5-flash
• add a focused controller test to keep the preset endpoint and model stable

Tests

• bun test controller/tests/starter-presets.test.ts
• git diff --check
• git diff --cached --check
• Atlas live model catalog: 374 visible models, confirmed qwen/qwen3.5-flash and deepseek-ai/deepseek-v4-pro

Note: attempted bun install --cwd controller --frozen-lockfile, but this local machine is out of disk space (ENOSPC while extracting tarballs), so full controller install/typecheck could not be run here.

[0xSero]

Keeping open for rework. Atlas Cloud is aligned and the intended preset is small, but recreate it from current dev and verify the real keyed onboarding and first-chat surface; static config alone is insufficient.

[0xSero]

Closing to keep the review queue actionable. The product idea may remain useful, but this dirty historical branch targets release-only main and is not a reviewable implementation. Recreate only the still-current slice from current dev.