v0.28.1

Fixed

• The forged-namespace warning (an unprefixed source whose bare item name
  contains :) no longer comes from the catalog scan, which ran on every
  read-only surface and re-ran on the probe TUI's ~1s poll tick, repeating the
  line into the alternate screen. meld and learn emit it at the point the
  user decides to trust the source, review reports it as a forged-namespace
  advisory, and recall/probe/introspect stay quiet (DSC-101).
• The scan's other degraded-state warnings (a linked source whose directory is
  gone, an item manifest that will not parse, an unsafe item name, a registry
  entry dropped by revalidation) are muted while the TUI owns the terminal and
  restored when it gives it back. Each reports a persistent condition, so on the
  poll tick it was redrawn into the alternate screen every second. Outside the
  TUI every one of them still prints (DSC-102).