fix: add mempalace-mcp console entry point for pipx/uv compatibility

The MCP server config used `python -m mempalace.mcp_server` which fails
when mempalace is installed via pipx or uv, since the system python
cannot find the module in the isolated venv. Adding a `mempalace-mcp`
console_scripts entry point ensures the MCP server works regardless of
installation method (pip, pipx, uv, conda).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

examples/mcp_setup.md

@@ -5,13 +5,13 @@
 Run the MCP server:
 
 ```bash
-python -m mempalace.mcp_server
+mempalace-mcp
 ```
 
 Or add it to Claude Code:
 
 ```bash
-claude mcp add mempalace -- python -m mempalace.mcp_server
+claude mcp add mempalace -- mempalace-mcp
 ```
 
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