Function format_copy_block 

pub fn format_copy_block(lines: &[&str], color: bool) -> String

Format a “copy this” block — content framed by horizontal rules but with no vertical border characters, so the user can select and paste the content directly without stripping │ symbols.

  ── copy ─────────────────────────────────────────────────
    "seshat": {
      "command": "seshat"
    }
  ─────────────────────────────────────────────────────────

• Top rule contains " copy " as a visual cue.
• Both rules are dimmed when color is true.
• Content lines are printed with 4-space indent, default terminal color.
• Width is fixed at HEADER_WIDTH characters (60), matching section headers.