fix(files): pass directory into context panel binary open guard

Scope context-file open validation to the active project directory so
binary opens resolve against the correct workspace root.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

packages/ui/src/lib/contextFileOpenGuard.ts

@@ -2,11 +2,11 @@ import type { FilesAPI } from '@/lib/api/types';
 import { MAX_OPEN_FILE_LINES, countLinesWithLimit } from '@/lib/fileOpenLimits';
 import { getCurrentIntlLocale } from '@/lib/i18n';
 import { formatMessage, useI18nStore } from '@/lib/i18n/store';
+import { runtimeFetch } from '@/lib/runtime-fetch';
+import { isBinaryFile, isImageFile, isPdfFile, looksLikeBinaryText } from '@/lib/toolHelpers';
 
 const t = (key: Parameters<typeof formatMessage>[1], params?: Parameters<typeof formatMessage>[2]) =>
   formatMessage(useI18nStore.getState().dictionary, key, params);
-import { runtimeFetch } from '@/lib/runtime-fetch';
-import { isBinaryFile, isImageFile, isPdfFile, looksLikeBinaryText } from '@/lib/toolHelpers';
 
 export type ContextFileOpenFailureReason = 'too-large' | 'missing' | 'unreadable' | 'binary';
 
@@ -14,6 +14,10 @@ export type ContextFileOpenValidationResult =
   | { ok: true }
   | { ok: false; reason: ContextFileOpenFailureReason };
 
+export type ContextFileOpenOptions = {
+  directory?: string;
+};
+
 const classifyReadError = (error: unknown): ContextFileOpenFailureReason => {
   const message = error instanceof Error ? error.message : String(error ?? '');
   const normalized = message.toLowerCase();
@@ -31,16 +35,27 @@ const classifyReadError = (error: unknown): ContextFileOpenFailureReason => {
   return 'unreadable';
 };
 
-const readFileContent = async (files: FilesAPI, path: string): Promise<string> => {
+const readFileContent = async (
+  files: FilesAPI,
+  path: string,
+  options?: ContextFileOpenOptions,
+): Promise<string> => {
   if (files.readFile) {
-    const result = await files.readFile(path, { optional: true });
+    const result = await files.readFile(path, {
+      optional: true,
+      directory: options?.directory,
+    });
     return result.content ?? '';
   }
 
   const params = new URLSearchParams({ path, optional: 'true' });
+  if (options?.directory) {
+    params.set('directory', options.directory);
+  }
   const response = await runtimeFetch(`/api/fs/read?${params.toString()}`, {
     // Avoid conditional requests (304 + empty body).
     cache: 'no-store',
+    headers: options?.directory ? { 'x-opencode-directory': options.directory } : undefined,
   });
   if (!response.ok) {
     const errorPayload = await response.json().catch(() => ({ error: response.statusText }));
@@ -55,13 +70,17 @@ const readFileContent = async (files: FilesAPI, path: string): Promise<string> =
  * Previewable/non-text binaries are allowed through so FilesView can show image/PDF
  * preview or the cannot-preview empty state — never by decoding them as editable text here.
  */
-export const validateContextFileOpen = async (files: FilesAPI, path: string): Promise<ContextFileOpenValidationResult> => {
+export const validateContextFileOpen = async (
+  files: FilesAPI,
+  path: string,
+  options?: ContextFileOpenOptions,
+): Promise<ContextFileOpenValidationResult> => {
   if (isBinaryFile(path) || isPdfFile(path) || isImageFile(path)) {
     return { ok: true };
   }
 
   try {
-    const content = await readFileContent(files, path);
+    const content = await readFileContent(files, path, options);
     if (looksLikeBinaryText(content)) {
       return { ok: false, reason: 'binary' };
     }