Rename cl-tui -> cl-tty, v0.9.0: Dialog System + Toast

Rename: cl-tty avoids naming collision with Quicklisp's cl-tui (naryl/cl-tui,
a cl-charms-based ncurses library). Our project is pure escape-sequence CL.

v0.9.0 adds:
- Dialog base class: modal overlay with backdrop, centered panel, size
  variants (:small/:medium/:large), stack-based management
- Dialog subclasses: alert, confirm, select-dialog, prompt-dialog
- Toast notifications: transient, top-right corner, auto-dismiss,
  colored variants (info/success/warning/error)
- 78 tests total, 100% passing

ASDF: read-time package references (+fiveam:+) replaced with
find-symbol so .asd loads without FiveAM pre-loaded

src/components/box-tests.lisp

@@ -1,7 +1,7 @@
-(defpackage :cl-tui-box-test
-  (:use :cl :fiveam :cl-tui.backend :cl-tui.layout :cl-tui.box)
+(defpackage :cl-tty-box-test
+  (:use :cl :fiveam :cl-tty.backend :cl-tty.layout :cl-tty.box)
   (:export #:run-tests))
-(in-package :cl-tui-box-test)
+(in-package :cl-tty-box-test)
 
 (def-suite box-suite :description "Box renderable tests")
 (in-suite box-suite)