fix(mcp): use wrapper scripts instead of venv symlinks

Replace direct python path in .mcp.json with run.sh wrapper scripts
that automatically locate the venv in cache or local directory.

Problem: .venv symlinks are gitignored, causing them to be wiped on
every git operation. The SessionStart hook should recreate them but
this was unreliable, leading to repeated MCP server failures.

Solution: run.sh scripts that:
- First check ~/.cache/claude-mcp-venvs/leo-claude-mktplace/{server}/.venv
- Fallback to local .venv if exists
- Exit with helpful error if neither found

This eliminates dependency on symlinks entirely - the scripts are
tracked in git and will always be present after clone/pull/update.

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

plugins/data-platform/.mcp.json

@@ -2,9 +2,8 @@
   "mcpServers": {
     "data-platform": {
       "type": "stdio",
-      "command": "${CLAUDE_PLUGIN_ROOT}/mcp-servers/data-platform/.venv/bin/python",
-      "args": ["-m", "mcp_server.server"],
-      "cwd": "${CLAUDE_PLUGIN_ROOT}/mcp-servers/data-platform"
+      "command": "${CLAUDE_PLUGIN_ROOT}/mcp-servers/data-platform/run.sh",
+      "args": []
     }
   }
 }