chore: update transitive dependencies and lay out the README like every other Colony repository

[MotherSphere]

Two remaining conformance gaps, in one PR.

Dependencies (DEP-1)

cargo update moves the four transitive crates that had fallen behind, and nothing else:

• equivalent 1.0.2 to 1.0.3
• tokio 1.53.2 to 1.53.3
• zerocopy and zerocopy-derive 0.8.62 to 0.8.63

Only Cargo.lock changes. This keeps the weekly Dependencies workflow ("Lockfile is current") green.

README layout (DOC-6)

The README now follows the skeleton in design/documentation.md and templates/program/README.md. Existing text is moved and retitled, not rewritten:

• Intro and Status blockquote first.
• ## Why Project Colony Resources: the SphereCord story.
• ## What it does: the former "How it works" and "What's in here", as subsections.
• ## Installation: the former "Consuming this repo". The colony-ui dependency now states its Rust 1.88 floor, and the themes.json / CSS path for non-Rust programs stays under "Everything else".
• ## Documentation: the design/ index table, plus links to templates/README.md, the crate README and SECURITY.md.
• Then Changing a colour, Guarantees, Shipping a program on Colony, Releasing colony-ui, Code signing policy, Privacy, License, in their existing order.

The release-please version markers around the colony-ui = "0.1.6" block are unchanged, so the release PR keeps bumping it.

Verification

• cargo test -p colony-ui --locked with the updated lockfile: 71 tests pass.
• Sorted-line diff of the old and new README: every original line is still present once; the only differences are the new headings, the two lead sentences, the Rust floor line and the documentation links, plus one rewrapped paragraph whose opening no longer pointed at text that moved.
• Every relative link in README.md resolves to an existing file; nothing in the repo linked to the two removed anchors (#design-rules, #consuming-this-repo).
• No en or em dash in the changed files.