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

org/modern-backend.org

@@ -215,7 +215,7 @@ and ~\\ for literal backslash.
 (test osc8-escape
   "OSC 8 hyperlink escape wraps text"
   (is (equal (cl-tty.backend::osc8-link "http://example.com" "click here")
-             (format nil "~C]8;;http://example.com~C\click here~C]8;;~C\"
+             (format nil "~C]8;;http://example.com~C\\click here~C]8;;~C\\"
                      #\Esc #\Esc #\Esc #\Esc))))
 #+END_SRC
 
@@ -269,7 +269,7 @@ characters for the four corners and edges.
   (is (equal (cl-tty.backend::border-char :rounded :top-left) "╭"))
   (is (equal (cl-tty.backend::border-char :rounded :horizontal) "─"))
   (is (equal (cl-tty.backend::border-char :rounded :vertical) "│"))
-  (is (equal (cl-tty.backend::border-char :rounded :bottom-right) "╯"))
+  (is (equal (cl-tty.backend::border-char :rounded :bottom-right) "╯")))
 #+END_SRC
 
 ** Border characters --- double style
@@ -281,7 +281,20 @@ Confirms that =:double= style maps to double-line box-drawing characters.
   "modern-border-char returns double-line chars"
   (is (equal (cl-tty.backend::border-char :double :top-left) "╔"))
   (is (equal (cl-tty.backend::border-char :double :horizontal) "═"))
-  (is (equal (cl-tty.backend::border-char :double :vertical) "║"))
+  (is (equal (cl-tty.backend::border-char :double :vertical) "║")))
+#+END_SRC
+
+** Suspend/resume backend
+
+Verifies that suspend-backend and resume-backend are no-ops when called
+on a backend not attached to a real terminal (no errors, return nil).
+
+#+BEGIN_SRC lisp :tangle ../src/backend/modern-tests.lisp
+(test suspend-resume-noop
+  "suspend-backend and resume-backend are no-ops in test context"
+  (let ((b (make-modern-backend)))
+    (is (null (multiple-value-list (suspend-backend b))))
+    (is (null (multiple-value-list (resume-backend b))))))
 #+END_SRC
 
 * Implementation
@@ -475,7 +488,7 @@ allows clickable text in terminals that support the protocol.
 #+BEGIN_SRC lisp :tangle ../src/backend/modern.lisp
 (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))
 #+END_SRC
 
@@ -586,6 +599,49 @@ leaves the alternate screen. Returns =nil= (via =(values)=).
   (values))
 #+END_SRC
 
+*** Suspend backend (temporary)
+
+Temporarily suspends the modern backend, restoring the terminal to a
+usable state so the shell (or parent process) can take over. Called
+before =SIGTSTP= or similar process suspension.
+
+Shows the cursor and exits the alternate screen buffer so the user
+sees the normal terminal content. Does NOT disable mouse modes or
+kitty keyboard — those would add ~100ms of overhead on every
+suspend/resume cycle and are harmless while suspended (the terminal
+just ignores the escape sequences).
+
+#+BEGIN_SRC lisp :tangle ../src/backend/modern.lisp
+(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))
+#+END_SRC
+
+*** Resume backend (after suspend)
+
+Re-initializes the modern backend after a suspension. Called after
+=SIGCONT= or similar process resume.
+
+Re-enters the alternate screen buffer and re-enables all input
+features (mouse, bracketed paste, kitty keyboard). The application
+is responsible for redrawing the full screen after resume.
+
+#+BEGIN_SRC lisp :tangle ../src/backend/modern.lisp
+(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))
+#+END_SRC
+
 ** Backend-size via ioctl
 
 *** backend-size