docs: rebuild README, visuals, and project wiki

[bifrost0x]

Summary

• rebuild the README as a concise GitHub landing page with a current quick start, product tour, security model, and links to deeper documentation
• add a versioned, comprehensive project wiki under docs/wiki/ covering installation, deployment, authentication, SSH/SFTP workflows, operations, and development
• replace README screenshots and GIFs with current product captures and add high-resolution implementation-grounded architecture diagrams
• update capture and documentation-surface contracts to keep public documentation aligned with the product

Verification

• python -m pytest tests -q — 1832 passed, 33 skipped
• npm run vendor:check
• npm run lint:js
• npm run test:js — 283 passed
• diagram accessibility and single-file checks for all four diagram sources
• git diff --check

Wiki publication

The repository has no automatic GitHub Wiki synchronization. After merge, the versioned pages in docs/wiki/ can be published to the live Wiki as a separate, traceable step.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 0ccb3ce8b9

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".