MessagePromptActivity

Unified full-screen modal prompt activity.

Detailed description

Driven by a positional QStringList push contract. The current schema (the v2/new schema) is:

push("MessagePromptActivity", QStringList{
  id,                  // echoed in pop
  severity,            // info|question|success|warning|danger|none
  title,               // plain-text title
  bodyMarkdown,        // may be empty
  iconPathOrEmpty,     // empty → severity stock icon
  spinnerFlag,         // "true" | "false"
  buttonCount,         // decimal integer ≥ 0
  // followed by buttonCount × 4 strings, in order:
  //   token, label, role, tooltip
  //   role ∈ default|cancel|destructive|neutral
})

The legacy schema is preserved for unmigrated callers:

push("MessagePromptActivity", QStringList{id, title, body, iconPath?, askConfirmation?});

Pop returns `[id, outcome]`, where outcome is the chosen button's token (legacy callers receive `"true"`/`"false"`).

See also Activity.