dsh-trading212: Trading 212 Read-Only Portfolio Workspace

The DeepSeek Harness (DSH) plugin `dsh-trading212` integrates Trading 212 portfolio data into DSH workflows. It provides a setup wizard, a responsive dashboard (with charts and privacy masking), read-only conversational tools, and Chinese/English support. Users must grant read-only access; after installation, they can view holdings and returns in `dsh`. It is intended for personal research only and does not place orders.