flowchart LR
    A[Markdown Text] --> B[Scan Links]
    B --> C{Protected Target URL?}
    C -- Yes --> D[Keep Intact]
    C -- No --> E[Probe HTTP Status]
    E --> F{Status 4xx / 5xx / Error?}
    F -- Yes --> G[Unwrap to Plain Text]
    F -- No --> D
    G --> H[Updated Markdown]
    D --> H