docs: restructure Platform accounts, security, and billing IA

[akristen]

To dos

• Evaluate _index pages and standardize across account + admins category
• Freshness sweep on FAQ section
• Edit weights of topics
• Notify TSEs, other stakeholders
• TW sign off

Summary

This PR restructures the Platform documentation into a clearer Accounts, Security, and Subscription and billing information architecture, with aliases so existing URLs keep working.

Work from these PRs was merged into this feature branch:

• docs: restructure Security IA and Hardened Docker Desktop nav #25957 (Security IA)
• docs: unify Accounts and Admin under /accounts/ #25960 (Accounts and Admin)
• docs: merge Subscription and Billing into one Platform section #25981 (Subscription and billing)

Accounts

• Moves organization, company, and admin content under Accounts.
• Splits individual-account docs into their own subsection.
• Removes the standalone Admin section; those pages now live under Accounts.

Security

• Publishes Security at /security/, matching other Platform sections.
• Groups authentication (SSO, 2FA, OIDC), access tokens, provisioning, and roles under Security.
• Leaves Enterprise Hardened Desktop and related enterprise security docs under Enterprise.
• Restores shipped Hardened Desktop and security FAQ URLs so they match main.

Subscription and billing

• Merges Subscription and Billing into a single Subscription and billing section.
• Drops the extra subcategory wrappers and nests billing tasks under Manage.
• Shortens the billing details sidebar label.

FAQs

• Consolidates Platform FAQs onto four pages: Accounts, Security, Subscription and billing, and Platform.
• Folds leftover general, container, and network/VM security FAQs into Platform FAQs.
• Folds SSO enforcement FAQs into the SSO FAQ.
• Templates FAQ pages with H2 topics and H3 questions, and limits the table of contents to H2.

Navigation and follow-ups

• Renames the manuals sidebar group from Platform to Accounts and admin, and updates the manuals landing heading and copy to match.
• Fixes the MSI install Settings Management link after the security path move.
• Updates CODEOWNERS, the labeler, and in-repo links to the new paths.

[netlify]

✅ Deploy Preview for docsdocker ready!

Name	Link
🔨 Latest commit	9ce82d3
🔍 Latest deploy log	https://app.netlify.com/projects/docsdocker/deploys/6a95e6677ac8f30008b7d425
😎 Deploy Preview	https://deploy-preview-25982--docsdocker.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.