review fixes: word-wrap hard-break, title-align, ASDF fix, edge cases

Fixes from subagent review:
- Word-wrap now hard-breaks words exceeding max-width (was returning
  un-truncated overflow strings)
- Box zero-size guard now catches any zero/single dimension (was only
  catching both zero together)
- Title-align now respected (:left/:center/:right) with proper positioning
- render-text declares (ignore spans) to suppress unused warning
- ASDF test-op fixed: run! → run-tests (symbol didn't exist)
- New test: box-single-column (width=1 renders nothing)
- Tightened word-wrap test: verifies hard-break produces both chunks
- Simplified word-wrap with cond instead of nested if/progn (avoided
  recurring paren-balance issue)

cl-tui.asd

@@ -38,4 +38,4 @@
     ((:file "box-tests")
      (:file "dirty-tests"))))
   :perform (test-op (o c)
-             (uiop:symbol-call :cl-tui-backend-test '#:run!)))
+             (uiop:symbol-call :cl-tui-backend-test '#:run-tests)))