GSD generates markdownlint compliant MD files

[PhilippWillms]

Problem or motivation

This feature will improve readbility in IDEs. In particular, the MD032 rule is violated quite often.

Proposed solution

When GSD agents generate markdown files, they run pymarkdownlint internally before shipping to user.

Alternatives considered

No response

Additional context

No response

[trek-e]

Implementation submitted in PR #1112.

Rather than adding an external linting dependency, this adds a built-in normalizeMd() function that normalizes markdown at all write points (STATE.md, frontmatter set/merge, template fill, milestone archives). Enforces MD022 (headings), MD031 (code blocks), MD032 (lists — the most commonly violated rule you mentioned), MD012 (consecutive blank lines), and MD047 (trailing newline).

The function is ~100 lines, zero dependencies, CRLF-safe, fence-aware, and idempotent. Includes 14 new tests.