feat: add syntax highlighting to /read command

Uses pygments with monokai style to highlight code by file extension,
with dimmed line numbers matching Claude Code's display style. Falls
back to plain text if pygments is unavailable. Also adds @filepath
shortcut in the REPL as an alias for /read.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: lzwjava

iclaw/commands/read.py

@@ -6,6 +6,23 @@ def _is_binary(data):
     return b"\x00" in data
 
 
+def _highlighted_lines(text, path):
+    try:
+        from pygments import highlight
+        from pygments.formatters import Terminal256Formatter
+        from pygments.lexers import TextLexer, get_lexer_for_filename
+        from pygments.util import ClassNotFound
+    except ImportError:
+        return text.splitlines()
+    try:
+        lexer = get_lexer_for_filename(path, stripnl=False)
+    except ClassNotFound:
+        lexer = TextLexer(stripnl=False)
+    formatter = Terminal256Formatter(style="monokai")
+    highlighted = highlight(text, lexer, formatter)
+    return highlighted.splitlines()
+
+
 def handle_read_command(arg):
     if not arg:
         print("Usage: /read <path>", file=sys.stderr)
@@ -38,9 +55,11 @@ def handle_read_command(arg):
     except UnicodeDecodeError:
         text = raw.decode("utf-8", errors="replace")
 
-    lines = text.splitlines()
-    print(f"\n{path} — {len(lines)} lines")
-    width = len(str(len(lines))) if lines else 1
-    for i, line in enumerate(lines, 1):
-        print(f"{i:>{width}}  {line}")
+    plain_lines = text.splitlines()
+    highlighted_lines = _highlighted_lines(text, path)
+    line_count = len(plain_lines)
+    print(f"\n{path} — {line_count} lines")
+    width = len(str(line_count)) if line_count else 1
+    for i, line in enumerate(highlighted_lines, 1):
+        print(f"\033[2m{i:>{width}}\033[0m  {line}")
     print()

iclaw/main.py

@@ -138,6 +138,9 @@ def main():
             arg = parts[1] if len(parts) > 1 else None
             handle_read_command(arg)
             continue
+        if user_input.startswith("@") and not any(c.isspace() for c in user_input):
+            handle_read_command(user_input)
+            continue
         if user_input == "/provider_model":
             p, t = handle_model_provider_command(CONFIG_PATH, model_provider)
             if t: