v0.7.0: Select dropdown with fuzzy filter

Select widget: list of options with keyboard navigation (up/down/enter/esc,
ctrl+n/p), case-insensitive substring filter with character-set Jaccard
fuzzy fallback, category headers, viewport culling, on-select callback.

Fixed from subagent review:
- Category filter return-from bug: categories kept in filtered set
- Dead trigram code removed (string-trigrams, trigram-score)
- Exports cleaned up (removed unused trigram exports)
- Character-set Jaccard replaces trigrams (better for short strings)

25 select tests, 100% GREEN.
196 total (27 backend + 58 box + 60 input + 26 scrollbox/tabbar + 25 select)

cl-tui.asd

@@ -2,7 +2,7 @@
 (asdf:defsystem :cl-tui
   :description "Reusable Common Lisp Terminal UI Framework"
   :author "Amr Gharbeia"
-  :version "0.6.0"
+  :version "0.7.0"
   :license "TBD"
   :depends-on (:fiveam :sb-posix)
   :components
@@ -32,7 +32,10 @@
      ;; Container components (v0.6.0)
      (:file "container-package" :depends-on ("package" "input-package"))
      (:file "scrollbox" :depends-on ("container-package" "dirty" "box"))
-     (:file "tabbar" :depends-on ("container-package" "dirty" "box"))))
+     (:file "tabbar" :depends-on ("container-package" "dirty" "box"))
+     ;; Select widget (v0.7.0)
+     (:file "select-package" :depends-on ("package" "input-package"))
+     (:file "select" :depends-on ("select-package" "dirty" "box"))))
   :in-order-to ((test-op (test-op :cl-tui-tests))))
 
 (asdf:defsystem :cl-tui-tests
@@ -52,12 +55,14 @@
      (:file "render-tests")
      (:file "theme-tests")
      (:file "input-tests")
-     (:file "scrollbox-tabbar-tests" :pathname "../../tests/scrollbox-tabbar-tests.lisp"))))
+     (:file "scrollbox-tabbar-tests" :pathname "../../tests/scrollbox-tabbar-tests.lisp")
+     (:file "select-tests" :pathname "../../tests/select-tests.lisp"))))
   :perform (test-op (o c)
               (dolist (suite '((:cl-tui-backend-test "BACKEND-SUITE")
                               (:cl-tui-box-test "BOX-SUITE")
                               (:cl-tui-input-test "INPUT-SUITE")
-                              (:cl-tui-scrollbox-test "SCROLLBOX-SUITE")))
+                              (:cl-tui-scrollbox-test "SCROLLBOX-SUITE")
+                              (:cl-tui-select-test "SELECT-SUITE")))
                (let* ((pkg (find-package (first suite)))
                       (s (and pkg (find-symbol (second suite) pkg))))
                  (when s