feat(v4.0.0): reading a line and splitting it into words and numbers

The first layer of the compiler capsule, on the host node: TIB >IN SPAN
SOURCE BL EXPECT QUERY WORD ENCLOSE CONVERT NUMBER and the comment
words.  The definitions are text, v4/capsule/core.v4 (the core words
they rest on) and v4/capsule/input.v4, assembled by the text assembler,
which can now read a file.

EXPECT, QUERY, WORD and ENCLOSE behave as v3's.  CONVERT and NUMBER are
FORTH-79 (ruled 2026-10-04): any BASE, a double in the standard order,
and NUMBER returns a signed double or sets NODE-ERROR.

Executed at both cell widths against C and against values recorded from
the v3 binary.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

v4/include/v4/text.h

@@ -101,7 +101,7 @@ typedef struct {
 
     unsigned line;
     int      failed;
-    char     message[160];
+    char     message[224];
 } v4_text;
 
 /* Start assembling at word address `origin` of node `n`. */
@@ -115,6 +115,9 @@ void v4_text_constant(v4_text *t, const char *name, v4_cell value);
  * has been no error. */
 int v4_text_assemble(v4_text *t, const char *source);
 
+/* The same for the text in the file at `path`.  Its errors name the file. */
+int v4_text_assemble_file(v4_text *t, const char *path);
+
 /* Finish: every branch must have found its target.  Returns 1 if there has
  * been no error.  Assembling may continue afterwards. */
 int v4_text_finish(v4_text *t);