feat: add MemPalace Claude Code plugin with hooks and instructions

- Introduced README.md for plugin overview and installation instructions.
- Added hooks configuration in hooks.json for auto-save and pre-compact functionality.
- Implemented stop and pre-compact hooks in bash scripts for memory management.
- Created marketplace.json and plugin.json for plugin metadata and versioning.
- Developed skills and instructions for help, init, mine, search, and status functionalities.
- Added CLI commands for executing hooks and displaying skill instructions.
- Implemented hooks_cli.py for handling hook logic and JSON input/output.
- Enhanced instruction files for user guidance on setup and usage.
- Updated .gitignore to exclude additional files.
- Created GitHub Actions workflow for syncing plugin version on push.

.claude-plugin/skills/init/SKILL.md

@@ -0,0 +1,18 @@
+---
+name: init
+description: Set up MemPalace — install the package, initialize a palace, configure MCP server, and verify everything works.
+---
+
+Run the following command to get setup instructions, then follow them step by step:
+
+```bash
+mempalace instructions init
+```
+
+If the command fails (mempalace not installed yet), first install it:
+
+```bash
+pip install mempalace
+```
+
+Then run the instructions command again and follow the output.