fix(mcp): capture CLAUDE_PROJECT_DIR from PWD before cd

All MCP server run.sh scripts now capture the original working
directory as CLAUDE_PROJECT_DIR before changing to the script
directory. This fixes the branch detection issue where MCP tools
detected the plugin repo's branch instead of the user's project branch.

This is a follow-up fix to #231 - the original fix relied on
CLAUDE_PROJECT_DIR being set by Claude Code, but it isn't.
Now we capture it ourselves from PWD at startup time.

Closes #231 (proper fix)

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

mcp-servers/data-platform/run.sh

@@ -1,4 +1,8 @@
 #!/bin/bash
+# Capture original working directory before any cd operations
+# This should be the user's project directory when launched by Claude Code
+export CLAUDE_PROJECT_DIR="${CLAUDE_PROJECT_DIR:-$PWD}"
+
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 CACHE_VENV="$HOME/.cache/claude-mcp-venvs/leo-claude-mktplace/data-platform/.venv"
 LOCAL_VENV="$SCRIPT_DIR/.venv"