release: v1.5.1

[theodevelop]

Type of change

• Bug fix

What does this PR do?

Aggregated PR for v1.5.1 — 7 bug fixes across Flex and Bison parsers, all found
via issues (#30, #31) and a proactive audit of both parsers.

Flex fixes (PRs #32, #33, #35):

• lex: invalid regex error - quotes (in character set?) not recognized #30 — Escaped quotes (\", \') inside Flex quoted string patterns no longer trigger false flex/invalid-pattern
• lex: abbreviation not recognized #31 — {ABBR} on rule lines with no inline action (BOL anchor or next-line {) now correctly recorded as abbreviation references
• audit-A — Quoted strings with spaces in rawPattern no longer truncated at the space, fixing false flex/unreachable-rule duplicates
• audit-B — Standalone { as multi-line action opener no longer pushed as a spurious rule entry
• audit-C — Lowercase start condition names now recognized in all SC regex patterns
• audit-D — Single-tab action separator now matched, preventing false abbreviation references from C action bodies

Bison fixes (PR #36):

• audit-E — Lowercase/mixed-case tokens in %left/%right/%nonassoc now correctly recorded in doc.precedence, eliminating false bison/undeclared-token
• audit-F — $N references after nested sub-blocks in inline actions now detected via brace-depth scanner

Related issue

Closes #30, closes #31

How to test manually

See individual PRs #32, #33, #35, #36.

Checklist

• npm run compile passes with no new errors
• Tests added or updated (750 assertions, 0 failed)
• Manual test done in VS Code
• CHANGELOG.md updated
• No unintended files staged