fix: correct line info calculation in file command

- Fix LineInfo.fromString to handle single line references (L10) without requiring end line
- Improve file content chunking message with clearer instructions
- Make next chunk suggestion more accurate and only show when relevant
- Enhance readability of file output message by including total line count

Author: phodal

exts/devins-lang/src/main/kotlin/cc/unitmesh/devti/language/compiler/exec/FileInsCommand.kt

@@ -90,9 +90,16 @@ class FileInsCommand(private val myProject: Project, private val prop: String) :
             val code = content.split("\n")
                 .slice(0 until MAX_LINES)
                 .joinToString("\n")
+
+            // 计算合理的下一块行范围建议
+            val nextChunkStart = MAX_LINES + 1
+            val nextChunkEnd = minOf(size, MAX_LINES * 2)
+            
+            val suggestion = if (nextChunkEnd > nextChunkStart) {
+                "\nUse `filename#L${nextChunkStart}-L${nextChunkEnd}` to get next chunk of lines."
+            } else ""
 
-            val availableEndLine = minOf(size, MAX_LINES * 2)
-            "File too long, only show first $MAX_LINES lines.\n$code\nUse `filename#L${MAX_LINES}-L${availableEndLine}` to get more lines."
+            "File too long, only showing first $MAX_LINES lines of $size total lines.\n$code$suggestion"
         } else {
             content
         }

exts/devins-lang/src/main/kotlin/cc/unitmesh/devti/language/compiler/model/LineInfo.kt

@@ -7,7 +7,7 @@ data class LineInfo(
     val endColumn: Int = 0
 ) {
     companion object {
-        private val regex = Regex("""L(\d+)(?:C(\d+))?(?:-L(\d+)(?:C(\d+))?)?""")
+        private val regex = Regex("""L(\d+)(?:C(\d+))?(?:-L(\d+)(?:C(\d+))?)?""") 
 
         /**
          * Convert a string to a `TextRange`, if possible. The string should be in the format: "filepath#L1-L12",
@@ -21,7 +21,7 @@ data class LineInfo(
 
             val startLine = matchResult.groupValues[1].toIntOrNull() ?: return null
             val startColumn = matchResult.groupValues[2].toIntOrNull() ?: 0
-            val endLine = matchResult.groupValues[3].toIntOrNull() ?: return null
+            val endLine = matchResult.groupValues[3].toIntOrNull() ?: startLine
             val endColumn = matchResult.groupValues[4].toIntOrNull() ?: 0
 
             return LineInfo(startLine, endLine, startColumn, endColumn)