Publish GPT-Live reasoner skills and squad migration guides

[dev-seth-vapi]

Description

• Publish the held Reasoner skills guide: choosing procedures, writing descriptions, base versus skill tools, dashboard/API/Markdown/Composer authoring, and testing.
• Restore the squad-to-one-assistant migration walkthrough and skills guidance in overview, conversation design, tools, settings, and troubleshooting.
• Match the landed implementation's unload behavior, naming constraints, and prompt composition. Preserve the six published illustrations and inline examples.

Testing Steps

• Compare fields, limits, activation and unloading against the landed implementation of VapiAI/vapi#21651.
• Validate with Fern and check the diff for whitespace errors.
• Review the hosted preview, navigation, squad migration, and final skill-unloading wording.
• Preview: https://vapi-preview-01a0f891-e762-70a7-81e2-616ba571fd63.docs.buildwithfern.com/gpt-live/skills
• Production verification follows merge.

[lightsage-app]

Lightsage docs evals

Lightsage could not queue docs evals for this PR.

Docs URL: https://vapi-preview-01a0f891-e762-70a7-81e2-616ba571fd63.docs.buildwithfern.com/gpt-live/skills
Commit: 67eff87
Reason: No custom evals are selected for GitHub PR evals. Open Lightsage > Custom Evals and enable the GitHub checkbox for at least one custom eval.

[github-actions]

🌿 Preview your docs: https://vapi-preview-01a0f891-e762-70a7-81e2-616ba571fd63.docs.buildwithfern.com