fix: cap inline selection context to 500 chars, send preview for large selections

Selections over 500 chars no longer send full text to the AI prompt.
Instead, a head/tail preview (first and last 3 lines, trimmed to 80
chars each) is sent with file path and line range, instructing the
AI to use the Read tool for full content.

Author: abose

src-node/claude-code-agent.js

@@ -147,11 +147,25 @@ exports.sendPrompt = async function (params) {
 
     // Prepend selection context to the prompt if available
     let enrichedPrompt = prompt;
-    if (selectionContext && selectionContext.selectedText) {
-        enrichedPrompt =
-            "The user has selected the following text in " + selectionContext.filePath +
-            " (lines " + selectionContext.startLine + "-" + selectionContext.endLine + "):\n" +
-            "```\n" + selectionContext.selectedText + "\n```\n\n" + prompt;
+    if (selectionContext) {
+        if (selectionContext.selectedText) {
+            enrichedPrompt =
+                "The user has selected the following text in " + selectionContext.filePath +
+                " (lines " + selectionContext.startLine + "-" + selectionContext.endLine + "):\n" +
+                "```\n" + selectionContext.selectedText + "\n```\n\n" + prompt;
+        } else {
+            let previewSnippet = "";
+            if (selectionContext.selectionPreview) {
+                previewSnippet = "\nPreview of selection:\n```\n" +
+                    selectionContext.selectionPreview + "\n```\n";
+            }
+            enrichedPrompt =
+                "The user has selected lines " + selectionContext.startLine + "-" +
+                selectionContext.endLine + " in " + selectionContext.filePath +
+                ". Use the Read tool with offset=" + (selectionContext.startLine - 1) +
+                " and limit=" + (selectionContext.endLine - selectionContext.startLine + 1) +
+                " to read the selected content if needed." + previewSnippet + "\n" + prompt;
+        }
     }
 
     // Run the query asynchronously — don't await here so we return requestId immediately

src/core-ai/AIChatPanel.js

@@ -506,15 +506,31 @@ define(function (require, exports, module) {
         // Gather selection context if available and not dismissed
         let selectionContext = null;
         if (_lastSelectionInfo && !_selectionDismissed && _lastSelectionInfo.selectedText) {
+            const MAX_INLINE_SELECTION = 500;
+            const MAX_PREVIEW_LINES = 3;
+            const MAX_PREVIEW_LINE_LEN = 80;
             let selectedText = _lastSelectionInfo.selectedText;
-            if (selectedText.length > 10000) {
-                selectedText = selectedText.slice(0, 10000);
+            let selectionPreview = null;
+            if (selectedText.length > MAX_INLINE_SELECTION) {
+                const lines = selectedText.split("\n");
+                const headLines = lines.slice(0, MAX_PREVIEW_LINES).map(function (l) {
+                    return l.length > MAX_PREVIEW_LINE_LEN ? l.slice(0, MAX_PREVIEW_LINE_LEN) + "..." : l;
+                });
+                const tailLines = lines.length > MAX_PREVIEW_LINES * 2
+                    ? lines.slice(-MAX_PREVIEW_LINES).map(function (l) {
+                        return l.length > MAX_PREVIEW_LINE_LEN ? l.slice(0, MAX_PREVIEW_LINE_LEN) + "..." : l;
+                    })
+                    : [];
+                selectionPreview = headLines.join("\n") +
+                    (tailLines.length ? "\n...\n" + tailLines.join("\n") : "");
+                selectedText = null;
             }
             selectionContext = {
                 filePath: _lastSelectionInfo.filePath,
                 startLine: _lastSelectionInfo.startLine,
                 endLine: _lastSelectionInfo.endLine,
-                selectedText: selectedText
+                selectedText: selectedText,
+                selectionPreview: selectionPreview
             };
         }