v1.4.0

Minor release: a new worktree-aware write boundary, plus several false-positive reductions in command parsing.

• feat: worktree-aware boundary — deny writes into sibling checkouts by @karlkfi in #67
• feat: resolve literal in-command variable assignments before flagging runtime-expanded args by @karlkfi in #63
• feat: exempt same-project sibling session scratch reads by @karlkfi in #65
• feat: resolve whitelisted pure substitutions in cd targets by @karlkfi in #64
• fix: eliminate false-positive file-arg tokens (comments, heredoc bodies, literal $) by @karlkfi in #66

Full Changelog: v1.3.0...v1.4.0