fix(dist): resolve symlinks in the bundle launcher (curl install was broken)

install.sh symlinks ~/.local/bin/codegraph -> the bundle launcher, but the
launcher derived its dir from $0, which is the symlink path — so it looked for
`node` next to the symlink and failed with `exec: .../node: not found`. Follow
the symlink chain to the real bundle dir first. (npm was unaffected — the shim
invokes the launcher by absolute path.) Verified via the symlinked install path
in a clean no-Node Linux container.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>