Remove the static `version: "1.0.0"` field from plugin.json to enable
Claude Code's git SHA-based version detection and automatic updates.
Previously, the presence of a version field caused Claude Code to use
static version string comparison instead of git commit SHA comparison,
preventing `/plugin update` from detecting new commits.
This change aligns with the pattern used by all official Anthropic
plugins in claude-plugins-official marketplace.
Fixes#33
