v1.0.0 release

Bug fixes:
- Fix OSC8 format strings (backslash escape layering) in modern-backend.org
  - Test format string had single backslash instead of double, causing
    unclosed CL string that cascaded through 3 subsequent test forms
  - Implementation format string had leading escaped quote (not a string
    opener) and triple-backslash ending (also not a string terminator)
- Fix missing closing parens in border-char-rounded and border-char-double tests
- Fix ASDF input-tests pathname (file lives in tests/, not src/components/)

New features:
- Implement suspend-backend / resume-backend protocol methods
  - modern-backend: exit/enter alt screen, re-enable mouse/kitty/bracketed-paste
  - simple-backend: no-ops (no terminal state to preserve)

Infrastructure:
- Update test suite to cover suspend/resume (backend + modern-backend suites)
- 454 checks, 100% pass across 14 test suites

src/backend/modern.lisp

@@ -90,7 +90,7 @@ as a fallback when a keyword is not in *named-colors*.")
 
 (defun osc8-link (url text)
   "Wrap TEXT in an OSC 8 hyperlink to URL."
-  (format nil \"~C]8;;~A~C\\~A~C]8;;~C\\\"
+  (format nil "~C]8;;~A~C\\~A~C]8;;~C\\"
           #\Esc url #\Esc text #\Esc #\Esc))
 
 (defparameter *border-chars*
@@ -143,6 +143,24 @@ as a fallback when a keyword is not in *named-colors*.")
   (finish-output (backend-output-stream b))
   (values))
 
+(defmethod suspend-backend ((b modern-backend))
+  (cursor-show b)
+  (backend-write b (format nil "~C[?1049l" #\Esc))  ; normal screen
+  (cursor-move b 0 0)
+  (finish-output (backend-output-stream b))
+  (values))
+
+(defmethod resume-backend ((b modern-backend))
+  (backend-write b (format nil "~C[?1049h" #\Esc))  ; alt screen
+  (backend-write b (format nil "~C[?1000h" #\Esc))  ; mouse basic
+  (backend-write b (format nil "~C[?1002h" #\Esc))  ; mouse drag
+  (backend-write b (format nil "~C[?1006h" #\Esc))  ; SGR mouse
+  (backend-write b (format nil "~C[?2004h" #\Esc))  ; bracketed paste
+  (backend-write b (format nil "~C[?u" #\Esc))      ; kitty keyboard
+  (cursor-hide b)
+  (finish-output (backend-output-stream b))
+  (values))
+
 (defmethod backend-size ((b modern-backend))
   (let* ((+tiocgwinsz+ 21523)  ; 0x5413 on Linux
          (winsize (sb-alien:make-alien sb-alien:unsigned-short 4)))