fix(tools): honor fsPolicy.workspaceOnly in image/pdf tool localRoots

PR #28822 fixed the Write/Edit tools to respect `tools.fs.workspaceOnly`,
but the image and PDF tools still unconditionally include default local
roots (`~/.openclaw/media`, `~/.openclaw/agents`, etc.) when computing
the `localRoots` allowlist for non-sandbox mode.

When `fsPolicy.workspaceOnly` is true, restrict `localRoots` to only the
workspace directory so that files outside the workspace are rejected by
`assertLocalMediaAllowed()`.

Relates to #31716

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

src/agents/tools/pdf-tool.ts

@@ -339,8 +339,11 @@ export function createPdfTool(options?: {
       : DEFAULT_MAX_PAGES;
 
   const localRoots = (() => {
-    const roots = getDefaultLocalRoots();
     const workspaceDir = normalizeWorkspaceDir(options?.workspaceDir);
+    if (options?.fsPolicy?.workspaceOnly) {
+      return workspaceDir ? [workspaceDir] : [];
+    }
+    const roots = getDefaultLocalRoots();
     if (!workspaceDir) {
       return roots;
     }