v0.0.18

fix(flowchart): encode quotes in unquoted labels (emoji tip case) (#52)

* feat(flowchart): add invalid fixture for quotes inside unquoted label with emoji tip\n\n- Add test to ensure safe autofix encodes inner quotes to "\n- Regenerate previews (invalid page updated)

* fix(flowchart): detect '@' inside unquoted square-bracket labels and wrap via autofix\n\n- Diagnostics: new code FL-LABEL-AT-IN-UNQUOTED\n- Autofix: reuse parentheses-in-unquoted handler to wrap label (non-parallelogram)\n- Add invalid fixture: label-with-at-sign.mmd\n- Add test-fixes case; regenerate previews

* feat(flowchart): handle backticks in inline edge labels\n\n- Semantics: new diagnostic FL-EDGE-LABEL-BACKTICK (error) in inline link text\n- Autofix: convert inline edge label to pipe label, strip backticks, encode " to "\n- Also sanitize backticks when wrapping unquoted paren labels; parallelogram fallback too\n- Add invalid fixtures: edge-label-backticks, label-with-at-sign\n- Update previews and generator to fail only on --fix=all changes

* tests/fixtures(flowchart): add invalid cases for '@' in unquoted label, emoji-quote tip, and backticked inline edge label; regenerate previews