Linting + Rules Improvements

[ryansann]

Summary

This prepares okftool for v0.2.0 with a richer diagnostics/rule model for downstream consumers like okfview.

Key changes:

• Adds canonical namespaced rule IDs, e.g. frontmatter/require-description, topology/no-orphan-concepts
• Keeps old flat rule IDs working as aliases in config, overrides, inline disables, and okftool explain
• Expands rule metadata with category, category name, aliases, rationale, help text, docs path, default severity, and fixability
• Enriches diagnostics with rule/category metadata so UIs can group and explain findings more effectively
• Exposes rule descriptors through the wasm API
• Updates CLI rules, explain, and SARIF output to use the richer rule metadata
• Updates presets, docs, fixtures, and tests to use canonical rule IDs
• Bumps workspace/crates to 0.2.0

Testing

• cargo fmt --all --check
• cargo test
• cargo package -p okftool-core --allow-dirty
• cargo publish -p okftool-core --dry-run --allow-dirty
• npm package dry-run/build checks for the wasm package