chore: rename marketplace to Leo Claude Marketplace

Update all references from old names to new marketplace identity:
- support-claude-mktplace → leo-claude-mktplace (URLs)
- lm-claude-plugins → leo-claude-mktplace (repo name)
- Claude Code Marketplace → Leo Claude Marketplace (display name)

Files updated:
- Core docs (CLAUDE.md, README.md, CHANGELOG.md)
- Documentation (CANONICAL-PATHS, CONFIGURATION, UPDATING, COMMANDS-CHEATSHEET)
- Marketplace manifest and all 9 plugin.json files
- Plugin READMEs and MCP server READMEs
- Setup script and label taxonomy reference

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

scripts/setup.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# setup.sh - Initial setup for lm-claude-plugins
+# setup.sh - Initial setup for Leo Claude Marketplace
 #
 # Usage: ./scripts/setup.sh
 #
@@ -265,7 +265,7 @@ print_report() {
 # --- Main ---
 main() {
     echo "=============================================="
-    echo "  lm-claude-plugins Setup (v3.0.0)"
+    echo "  Leo Claude Marketplace Setup (v3.0.0)"
     echo "=============================================="
     echo ""