Fix skill installation and clean up duplicates

- Fix skill key lookup to accept both stored keys and install key format from list command
- Fix source_directory calculation when skills_path is set in repository config
- Remove duplicate skills from old jeremylongshore/claude-code-plugins-plus repository
- Update repository config to use correct jeremylongshore/claude-code-plugins-plus-skills

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: James Zhu

code_assistant_manager/fetching/parsers.py

@@ -48,6 +48,17 @@ def parse_from_file(
         except ValueError:
             source_directory = directory
 
+        # If skills_path is set, source_directory should be relative to skills_path
+        if repo_config.path:
+            skills_path = Path(repo_config.path)
+            try:
+                # Try to make source_directory relative to skills_path
+                full_skills_path = repo_root / skills_path
+                source_directory = str(skill_dir.relative_to(full_skills_path))
+            except ValueError:
+                # If we can't make it relative, keep the full path but warn
+                logger.warning(f"Skill directory {skill_dir} is not under skills_path {repo_config.path}")
+
         # Create skill entity
         skill = Skill(
             key=self.create_entity_key(repo_config, directory),