docs: improve SEO titles and descriptions across docs

[mintlify]

Summary

Audits all MDX pages for SEO metadata quality and fills in missing or fixes weak title and description frontmatter on 783 pages so each page has a unique, descriptive entry under standard SEO length guidelines.

Changes

• Added or rewrote description frontmatter on pages that were missing one, too short (<130 chars), too long (>160 chars), or duplicated across pages — descriptions now target 130–160 chars and summarize the specific page content.
• Differentiated duplicate descriptions between mirrored x-api/ (Standard X API v2) and enterprise-api/ (Enterprise X API v2) sections by appending a tier label so each page has a unique snippet.
• Added missing title frontmatter on a small number of pages whose OpenAPI operation references do not supply a spec summary (e.g. create-replay-job, get-marketplace-handle-availability, get-ai-trends-by-id, community-notes/introduction).
• Generated unique descriptions for all auto-generated Python and TypeScript XDK reference pages so each class, interface, module, and model has its own SEO snippet.
• Populated previously empty placeholder pages enterprise-api/tools-and-libraries.mdx and x-api/migrate/ready-to-migrate.mdx with minimal title + description frontmatter.
• Did not modify OpenAPI spec files or pages whose openapi: operation supplies a description in the spec.

Context

Pages with openapi: operation references inherit summary and description from openapi.json; those were left to use the spec metadata. Audit after the change reports 0 missing/short/long/duplicate descriptions across all non-translation, non-snippet MDX files.

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Project	Status	Preview	Updated (UTC)
x-corp	🟢 Ready	View Preview	May 29, 2026, 10:25 PM

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