feat(rules-git): read local git config for recursive submodule check before invoking git binary

Parse .git/config and config.worktree files directly to determine submodule.recurse
setting without needing a git binary invocation. Resolves gitdir and commondir
from worktree .git files. Includes and includeIf directives conservatively
treat as enabling recursive submodules. Falls back to git binary only when local
config is absent or inconclusive; returns false instead of true when git binary
is unavailable but local config is readable.

Author: kenryu42