[docs/faq] Write new FAQ entries covering GPU virtualization, scheduling, and ecosystem integration

[mesutoezdil]

Context

This issue is part of the HAMi v2.9.0 Documentation Revamp Plan (WS6 - FAQ Revamp).

This is the writing phase of the FAQ revamp. It depends on the question collection work in #415. Do not start this issue until #415 is complete and a list of candidate questions is available.

Before you start

Please reach out to the maintainers before picking this up:

• @rootsongjc (author, architecture decisions)
• @mesutoezdil (revamp reviewer, scope alignment)

Also check #415 for the list of collected questions before writing.

Scope

Write new FAQ entries in docs/faq.md covering at minimum:

• GPU virtualization model: how HAMi virtualizes GPU resources and what the limits are
• Scheduling interaction: how HAMi integrates with the Kubernetes scheduler, and how it interacts with other schedulers such as Volcano
• Ecosystem integration: common questions about using HAMi alongside vLLM, monitoring tools, and cloud providers

Each entry must follow the existing FAQ format:

• Question as a heading
• Direct answer in the first sentence
• Supporting detail if needed
• Link to relevant documentation page where applicable

Acceptance criteria

• At minimum 5 new FAQ entries added
• Each entry answers a question sourced from [docs/faq] Collect real user questions from GitHub issues and community channels #415
• No first-person language
• No marketing language
• Code blocks have language specifiers
• Admonitions use Docusaurus syntax
• Chinese translation not required for initial PR but is welcome
• DCO sign-off required on every commit (git commit -s)

Dependency

Blocked by #415.