v5.9.1

Fixed

• First-run banner now delivered via the MCP server instructions field
  (RDR-126 §3 amendment, nexus-vlo2b). Live Claude Desktop testing (P6-B)
  found the 5.9.0 banner was delivered into the tool result but the Desktop
  model paraphrased it away, so the user never saw it. The banner is now
  injected into instructions at the initialize handshake (standing session
  context, framed as a relay instruction), with the content-prepend retained
  only as an injection-failure recovery path. This is a delivery-mechanism
  change; user-visibility on Desktop is being re-verified.