fix(docs): migrate GitHub links to openmaxai

[eric-sss89]

What

• migrate all 27 tracked coco-xyz GitHub references to openmaxai
• update VitePress JSON-LD, social/footer links, and edit-page links
• update HxA Suite/Teams, Release video, raw testimonial image, and Use Case contribution/source URLs
• update the root handoff repository reference

Why

The repositories have moved to the openmaxai GitHub organization, so documentation links and generated site metadata should use the canonical locations.

Test

• Default VitePress build
• VITEPRESS_BASE=/docs/ VitePress build
• Source and both generated outputs contain zero coco-xyz references
• Generated GitHub/edit/Release link assertions passed for both outputs
• Representative organization, HxA Teams, edit-page, Release video, and raw image URLs returned HTTP 200
• node --check docs/.vitepress/config.mjs
• git diff --check

Review checklist

• No secrets or credentials in code
• Changes match the PR title
• Breaking changes documented (none)

[Nanyan]

LGTM — clean 1:1 replacement of coco-xyz → openmaxai across all 12 files. No functional changes.