S0b: console support as internal packages of the command #3

Part of #17. Design: docs/design.md §7.2.

Scope

The command's console support lives in the relix-cli module as internal packages. The module exports nothing, and nothing is published to Maven Central: this code is the command's implementation, not an API.

The earlier command's relix-console module (DarkCollective/relix) is the starting point. Its code is copied in and changed freely, and nothing keeps the two copies in step.

• render/: OutputFormat and its formatters (table, CSV, JSON; TSV and NDJSON follow in S2a), and a terminal renderer for a reference page's markdown.
• report/: the bundle JSON, provenance output and the optimisation report.
• io/: a ScriptLoader over files, so import resolves relative to the importing file.
• drivers/: download progress.
• Not here: the reference-page index. DocRegistry and DocEntry are not copied. relix doc uses the engine's lookup in relix-docs (Move the reference lookup into relix-docs: functions and front-end pages in one index relix-core#95).
• Not here: config/, or the earlier relix-env.json loader. The design drops that format (§8), so there is no profile loading to copy. Profiles and ${VAR} placeholders are new code in S1 (S1: command skeleton — script sources, exit codes, diagnostics, profiles, engine options #4).
• Tests come with the code, including the test that renders every worked example from the engine's reference pages and diffs the result against the table the page prints. A guard follows its renderer, so it runs against this command's table renderer and reads the engine's manuals artifact for the pinned version.

A need the engine's published API does not meet goes here, or into the engine when another embedder would need it too. It never goes into a separately published library.

Dependencies

• S0a (S0a: project build — Gradle, engine pin, boundary test, CI #2).

Acceptance

• The packages build and their tests pass here.
• module-info exports no package.
• The build publishes no Maven artifact.
• No class of the reference index (DocRegistry, DocEntry) is in the module.