Sprint B.5: add-LICENSE action (MIT/Apache-2.0) in [m] menu + vulp repo license

- src/license/: embedded templates, holder resolution (config > git user.name
  > account username), write path shared by TUI and CLI
- TUI: bulk-aware [m] entry over action_targets(), kind select + confirm,
  point-updates has_license/is_dirty, logs to activity (new License kind)
- CLI: vulp repo license <repo>...|--all [--kind] [--holder] [--json],
  skips already-licensed repos, exit 2/4 contract kept
- config: license_holder + default_license fields (TUI-editable)
- never overwrites an existing license, never auto-commits

src/hub/tabs_overview.rs

@@ -27,6 +27,7 @@ fn kind_color(kind: crate::activity::ActivityKind) -> Color {
         K::Todo    => Color::Yellow,
         K::Pr      => Color::Cyan,
         K::Issue   => Color::Yellow,
+        K::License => Color::Magenta,
     }
 }