docs: clarify hiding guarantees and credential handling

[okhsunrog]

Align the offline guide and threat model with current credential handling and network substitution behavior. Remove unsupported hiding and routing guarantees so users can distinguish concealment from tunnel retention.

• Correct SuperKey persistence and explain when trusted-token activation avoids saving a key.
• Clarify physical-network substitution, VPN bypass policy, kill-switch choices, and the limits of self-tests.
• Add a localized security and privacy article covering trust, partial protection, credentials, developer access, and debug reports.
• Fix the first-app setup order to avoid discarding unsaved role edits, and connect installation to the walkthrough.
• Add targeted heading links across English, Russian, and Chinese help; regenerate the guide index.
• Scope the threat model's policy-cache fallback and HTTP receive deadline claims to their implementations.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-12T19:03:11.914919Z	68c2142	PR opened

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