feat: lint reports sections that hold only template placeholders as Unfilled Template Sections (#94)

Files changed:
- CHANGES.md
- EVALS.md
- VERSION
- instructions/wiki-lint/SKILL.md
- instructions/wiki-manage/SKILL.md
- tools/CONTRACT.md
- tools/chemenu/blocks.py
- tools/chemenu/commands/lint.py
- tools/chemenu/evals/scorecard.py
- tools/chemenu/lint_core.py
- tools/chemenu/tests/test_blocks.py
- tools/chemenu/tests/test_evals.py
- tools/chemenu/tests/test_lint.py
- tools/chemenu/tests/test_pipeline_l0.py
- types/type-spec.md

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

instructions/wiki-manage/SKILL.md

@@ -47,7 +47,8 @@ requirements come from `tools/wikitool types describe <type>`.
 4. **Gather what the wiki already knows** - `tools/wikitool search` again, for the surrounding
    subjects - so the prose connects to existing pages instead of restating them.
 
-5. **Draft.** Fill in the generated skeleton's TODO sections, following the tone rules in
+5. **Draft.** Fill in the generated skeleton's TODO sections - `lint` reports a section still
+   made of nothing else as unfilled - following the tone rules in
    `kb/CONVENTIONS.md` § Tone. If `provenance:` is `sourced` or `mixed`, cite
    hard facts as you write them with `tools/wikitool cite add --page "<Title>" --source
    "Source - X"`, which also adds `X` to `sources:` - paste the `[^cite-id]` marker it prints.