Rename mermaid-preview-cli to mmdp

Add Homebrew tap and upgrade instructions to README

Add stdout confirmation, duplicate detection, cascade, and race-safe IPC

Move main.go to cmd/mermaid-preview-cli/

Gate listening URL behind --verbose, pass --verbose in E2E tests

Always print listening URL on stderr

Fix errcheck lint violations in IPC package

Add multi-window host, dock menu, and color-coded window tags

Merge pull request #6 from mxcoppell/feature/fade-animation-no-dock-icon

Add subtle fade-in animation and eliminate dock icon

Merge pull request #5 from mxcoppell/fix/fouc-and-search-highlight

Fix window flash during startup and improve search highlighting

Remove misleading claims and add pipe-only guidance for agents (#4)

Fix inaccurate claim in README Why section (#3)

Remove redundant binary description from README (#2)