v0.2.0: Text renderable with word-wrap and inline spans

- Text class with content, fg/bg, wrap-mode (:word or :none)
- Span class for inline styled segments (bold, italic, etc.)
- render-text dispatches through backend's draw-text
- word-wrap function splits text at word boundaries
- split-string utility for whitespace tokenization
- 9 new tests: creation, content, empty, truncation, word-wrap,
  single-word, span creation, span storage
- modern-backend now accepts :output-stream
- ASDF updated with text component
- 28 total component tests, 100% GREEN

src/components/text.lisp

@@ -0,0 +1,106 @@
+(in-package :cl-tui.box)
+
+;; ── Text Renderable ────────────────────────────────────────────
+
+(defclass span ()
+  ((text :initarg :text :accessor span-text)
+   (bold :initform nil :initarg :bold :accessor span-bold)
+   (italic :initform nil :initarg :italic :accessor span-italic)
+   (underline :initform nil :initarg :underline :accessor span-underline)
+   (reverse :initform nil :initarg :reverse :accessor span-reverse)
+   (dim :initform nil :initarg :dim :accessor span-dim)
+   (fg :initform nil :initarg :fg :accessor span-fg)
+   (bg :initform nil :initarg :bg :accessor span-bg)))
+
+(defun span (text &key bold italic underline reverse dim fg bg)
+  (make-instance 'span
+    :text text :bold bold :italic italic
+    :underline underline :reverse reverse :dim dim
+    :fg fg :bg bg))
+
+(defclass text ()
+  ((layout-node :initform (make-layout-node) :accessor text-layout-node
+     :initarg :layout-node)
+   (content :initform "" :initarg :content :accessor text-content)
+   (spans :initform nil :initarg :spans :accessor text-spans)
+   (fg :initform nil :initarg :fg :accessor text-fg)
+   (bg :initform nil :initarg :bg :accessor text-bg)
+   (wrap-mode :initform :word :initarg :wrap-mode :accessor text-wrap-mode)))
+
+(defun make-text (content &key fg bg wrap-mode width height spans)
+  (make-instance 'text
+    :content content
+    :fg fg :bg bg
+    :wrap-mode (or wrap-mode :word)
+    :spans spans
+    :layout-node (make-layout-node :direction :column
+                               :width width :height height)))
+
+(defun render-text (text-object backend)
+  "Render TEXT-OBJECT at its computed layout position using BACKEND."
+  (let ((ln (text-layout-node text-object))
+        (content (text-content text-object))
+        (fg (text-fg text-object))
+        (bg (text-bg text-object))
+        (wrap (text-wrap-mode text-object))
+        (spans (text-spans text-object)))
+    (let ((x (layout-node-x ln))
+          (y (layout-node-y ln))
+          (w (layout-node-width ln))
+          (h (layout-node-height ln)))
+      (when (or (zerop (length content)) (zerop w) (zerop h))
+        (return-from render-text (values)))
+      (if (eql wrap :none)
+          ;; No wrap — truncate to width
+          (let ((display (subseq content 0 (min (length content) w))))
+            (draw-text backend x y display fg bg))
+          ;; Word wrap
+          (let ((lines (word-wrap content w))
+                (max-lines h))
+            (loop for line in lines
+                  for row from 0 below max-lines
+                  do (draw-text backend x (+ y row) line fg bg)))))))
+
+(defun word-wrap (text max-width)
+  "Split TEXT into lines, each no longer than MAX-WIDTH characters.
+ Breaks at word boundaries when possible."
+  (if (or (zerop max-width) (zerop (length text)))
+      (list "")
+      (let ((words (split-string text))
+            (lines nil)
+            (current nil)
+            (current-len 0))
+        (dolist (word words)
+          (let ((word-len (length word)))
+            (if (and current (<= (+ current-len 1 word-len) max-width))
+                ;; Add to current line
+                (progn
+                  (push word current)
+                  (incf current-len (1+ word-len)))
+                ;; Start new line
+                (progn
+                  (when current
+                    (push (format nil "~{~A~^ ~}" (nreverse current)) lines))
+                  (setf current (list word))
+                  (setf current-len word-len)))))
+        (when current
+          (push (format nil "~{~A~^ ~}" (nreverse current)) lines))
+        (or (nreverse lines) (list "")))))
+
+(defun split-string (string)
+  "Split STRING into words separated by whitespace."
+  (loop with words = nil
+        with start = 0
+        with len = (length string)
+        while (< start len)
+        do (let ((ws-start (position-if (lambda (c) (find c '(#\Space #\Tab #\Newline)))
+                                        string :start start)))
+             (if ws-start
+                 (progn
+                   (when (> ws-start start)
+                     (push (subseq string start ws-start) words))
+                   (setf start (1+ ws-start)))
+                 (progn
+                   (push (subseq string start) words)
+                   (setf start len))))
+        finally (return (nreverse words))))