[chengggit]

Overview: Last pass before tagging v1.0.0 — full README rewrite, proper release notes, issue templates, and a few install and setup polishing.

• Setup: mcsr setup now offers to make mcsr a global command if it's missing (launcher on Windows, symlink on Linux), so it works even if the install-time step was skipped.
• Install script: default Linux path now respects $XDG_DATA_HOME (falls back to ~/.local/share), and prints a PATH export hint when ~/.local/bin isn't on PATH; post-install output points to mcsr setup instead of just --help.
• Fixes: mcsr import now requires at least one world directory (was silently running empty); missing-mod errors list mods by name with colored output.
• Docs: README rewritten with features, tracking behavior (Atum validation, seed capture, cheat detection, structure split normalization), Linux/Windows/manual install, and a dashboard screenshot.
• Release: real v1.0.0 release notes for the workflow, plus bug report / feature request issue templates.