release: provide a zero-setup install path for public users

[nao1215]

Roadmap: #1

Problem

The current public install story still assumes either:

• an existing Erlang/OTP runtime so users can run the released escript, or
• an existing Gleam project so users can invoke gleam run -m sqlode.

That is a much higher-friction entry point than sqlc, especially for users evaluating sqlode before they have committed to a Gleam stack.

Evidence

• README.md lists only two install paths: released escript or gleam add sqlode + gleam run
• .github/workflows/release.yml uploads a single sqlode escript artifact
• The generated release notes also tell users to download the escript and mention the Erlang/OTP runtime requirement

Expected

Provide at least one first-class install route that does not require users to already have Erlang/OTP or a local Gleam project.

Examples:

• publish a Homebrew tap formula
• ship standalone native binaries
• add an installer path that bundles the runtime

Keeping the escript path is fine, but it should not be the only public-facing option.

Why this matters

Public release adoption depends heavily on first-run friction.
sqlc users are used to brew install sqlc-level convenience, so the current install story will make evaluation slower and less likely.