v1.0.0: TUI support — resize events, with-terminal macro

- read-event now checks *terminal-resized-p* and returns :resize on SIGWINCH
- Added with-terminal convenience macro (detect → init → body → shutdown)
- Exported *terminal-resized-p* from cl-tty.input package
- Exported with-terminal from cl-tty.backend package
- Updated text-input.org with resize event integration and refactored tests
- Tests: 461 checks, 100% pass (93 input suite, +2 new test cases)

src/backend/package.lisp

@@ -20,6 +20,7 @@
    #:capable-p
    ;; Constructors
    #:make-simple-backend
+   #:with-terminal
    ;; Modern backend
    #:modern-backend #:make-modern-backend
    ;; Detection