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/simple.lisp

@@ -15,6 +15,12 @@
 (defmethod shutdown-backend ((b simple-backend))
   (values))
 
+(defmethod suspend-backend ((b simple-backend))
+  (values))
+
+(defmethod resume-backend ((b simple-backend))
+  (values))
+
 (defmethod backend-size ((b simple-backend))
   ;; Try ioctl, fall back to 80x24
   (values 80 24))