GRE-288: Retire temporary startup documentation

[HeadCase]

Summary

• rename the appliance guide to qualified-releases.md
• replace temporary startup wording with the qualified release workflow
• update README and deployment-test references
• preserve the media-stack and wg1 restrictions

Verification

• cargo fmt --all -- --check
• cargo clippy --workspace --all-targets --all-features -- -D warnings
• cargo test --workspace --all-targets --all-features
• cargo deny check
• cargo machete
• npm test
• focused deployment test: 16 passed
• standards review: no findings
• spec review: no findings

Linear: https://linear.app/headcase/issue/GRE-288/retire-temporary-startup-documentation-after-qualified-appliance