Fix automate unrunnable tools (#7311)

# Description of Changes

Fix automate unrunnable tools


## Problem

- Remove Image failed in Automate with `Tool operation not supported:
removeImage`
- Its registry entry had `operationConfig: undefined` even though the
config existed and was already tested
- The Automate picker only filtered on `supportsAutomate`, never on
`operationConfig` — so broken tools were selectable and failed only at
run time

## Fixes

- Wire up `removeImage` and `pageLayout` operation configs (both already
existed, just never registered)
- Exclude `validateSignature` (report tool, not on the operationConfig
seam) and `scannerEffect` (no frontend implementation) via
`supportsAutomate: false`
- Picker now also filters on `operationConfig`, so this class of bug
can't reach users again
- `overlay-pdfs` returns 400 instead of 500 when overlay files or mode
are missing
- Fix `new URL().pathname` Windows path bug that stopped 2 test suites
from loading

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have run `task check` to verify linters, typechecks, and tests
pass
- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#7-testing)
for more details.

Author: Frooodle

app/core/src/main/java/stirling/software/SPDF/controller/api/PdfOverlayController.java

@@ -61,6 +61,7 @@ public ResponseEntity<Resource> overlayPdfs(@ModelAttribute OverlayPdfsRequest r
         int overlayPos = request.getOverlayPosition();
 
         MultipartFile[] overlayFiles = request.getOverlayFiles();
+        validateOverlayFiles(overlayFiles);
         File[] overlayPdfFiles = new File[overlayFiles.length];
         List<File> tempFiles = new ArrayList<>(); // List to keep track of temporary files
 
@@ -120,10 +121,29 @@ public ResponseEntity<Resource> overlayPdfs(@ModelAttribute OverlayPdfsRequest r
         }
     }
 
+    // Both fields are declared required, but @ModelAttribute binding leaves them null when the
+    // caller omits them, which would otherwise surface as a 500 instead of a 400.
+    private void validateOverlayFiles(MultipartFile[] overlayFiles) {
+        if (overlayFiles == null || overlayFiles.length == 0) {
+            throw ExceptionUtils.createIllegalArgumentException(
+                    "error.overlayFilesRequired", "At least one overlay file is required");
+        }
+        for (MultipartFile overlayFile : overlayFiles) {
+            if (overlayFile == null || overlayFile.isEmpty()) {
+                throw ExceptionUtils.createIllegalArgumentException(
+                        "error.overlayFileEmpty", "Overlay files must not be empty");
+            }
+        }
+    }
+
     private Map<Integer, String> prepareOverlayGuide(
             int basePageCount, File[] overlayFiles, String mode, int[] counts, List<File> tempFiles)
             throws IOException {
         Map<Integer, String> overlayGuide = new HashMap<>();
+        if (mode == null) {
+            throw ExceptionUtils.createIllegalArgumentException(
+                    "error.invalidFormat", "Invalid {0} format: {1}", "overlay mode", "null");
+        }
         switch (mode) {
             case "SequentialOverlay":
                 sequentialOverlay(overlayGuide, overlayFiles, basePageCount, tempFiles);

frontend/editor/src/core/components/tools/automate/ToolSelector.tsx

@@ -34,13 +34,17 @@ export default function ToolSelector({
   const [shouldAutoFocus, setShouldAutoFocus] = useState(false);
   const containerRef = useRef<HTMLDivElement>(null);
 
-  // Filter out excluded tools (like 'automate' itself) and tools that don't support automation
+  // Filter out excluded tools (like 'automate' itself), tools that don't support
+  // automation, and tools with no operationConfig - the executor resolves a step
+  // through operationConfig, so offering one without it fails only at run time.
   const baseFilteredTools = useMemo(() => {
     return (
       Object.entries(toolRegistry) as [ToolId, ToolRegistryEntry][]
     ).filter(
       ([key, tool]) =>
-        !excludeTools.includes(key) && getToolSupportsAutomate(tool),
+        !excludeTools.includes(key) &&
+        getToolSupportsAutomate(tool) &&
+        Boolean(tool.operationConfig),
     );
   }, [toolRegistry, excludeTools]);
 

frontend/editor/src/core/data/automatableToolsHaveOperationConfig.test.tsx

@@ -0,0 +1,33 @@
+/**
+ * Registry invariant: the Automate picker offers a tool whenever it doesn't opt out via
+ * `supportsAutomate: false`, but automationExecutor resolves each step through the tool's
+ * `operationConfig`. A tool that is offered without one is selectable in the builder and
+ * only fails when the automation runs, with "Tool operation not supported: <toolId>".
+ *
+ * So a tool must either carry an operationConfig or declare supportsAutomate: false.
+ */
+import { describe, expect, test, vi } from "vitest";
+import { renderHook } from "@testing-library/react";
+import { useTranslatedToolCatalog } from "@app/data/useTranslatedToolRegistry";
+import { getToolSupportsAutomate } from "@app/data/toolsTaxonomy";
+
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({
+    t: (key: string, fallback?: string) => fallback ?? key,
+    i18n: { changeLanguage: vi.fn(), language: "en-US" },
+  }),
+  Trans: ({ children }: { children?: unknown }) => children,
+}));
+
+describe("automatable tools", () => {
+  test("every tool offered to Automate can be executed as a step", () => {
+    const { result } = renderHook(() => useTranslatedToolCatalog());
+
+    const offeredWithoutConfig = Object.entries(result.current.regularTools)
+      .filter(([, entry]) => entry && getToolSupportsAutomate(entry))
+      .filter(([, entry]) => !entry.operationConfig)
+      .map(([id]) => id);
+
+    expect(offeredWithoutConfig).toEqual([]);
+  });
+});

frontend/editor/src/core/data/useTranslatedToolRegistry.tsx

@@ -50,6 +50,8 @@ import { changeMetadataOperationConfig } from "@app/hooks/tools/changeMetadata/u
 import { signOperationConfig } from "@app/hooks/tools/sign/useSignOperation";
 import { cropOperationConfig } from "@app/hooks/tools/crop/useCropOperation";
 import { removeAnnotationsOperationConfig } from "@app/hooks/tools/removeAnnotations/useRemoveAnnotationsOperation";
+import { removeImageOperationConfig } from "@app/hooks/tools/removeImage/useRemoveImageOperation";
+import { pageLayoutOperationConfig } from "@app/hooks/tools/pageLayout/usePageLayoutOperation";
 import { extractImagesOperationConfig } from "@app/hooks/tools/extractImages/useExtractImagesOperation";
 import { replaceColorOperationConfig } from "@app/hooks/tools/replaceColor/useReplaceColorOperation";
 import { removePagesOperationConfig } from "@app/hooks/tools/removePages/useRemovePagesOperation";
@@ -526,6 +528,9 @@ export function useTranslatedToolCatalog(): TranslatedToolCatalog {
         maxFiles: -1,
         endpoints: ["validate-signature"],
         synonyms: getSynonyms(t, "validateSignature"),
+        // Reports on signatures rather than transforming the PDF, and its hook is
+        // not on the operationConfig seam, so it cannot run as an automation step.
+        supportsAutomate: false,
         automationSettings: null,
       },
 
@@ -755,6 +760,7 @@ export function useTranslatedToolCatalog(): TranslatedToolCatalog {
         subcategoryId: SubcategoryId.PAGE_FORMATTING,
         maxFiles: -1,
         endpoints: ["multi-page-layout"],
+        operationConfig: asRegistryConfig(pageLayoutOperationConfig),
         automationSettings: lazySettings(
           () => import("@app/components/tools/pageLayout/PageLayoutSettings"),
         ),
@@ -967,7 +973,7 @@ export function useTranslatedToolCatalog(): TranslatedToolCatalog {
         subcategoryId: SubcategoryId.REMOVAL,
         maxFiles: -1,
         endpoints: ["remove-image-pdf"],
-        operationConfig: undefined,
+        operationConfig: asRegistryConfig(removeImageOperationConfig),
         synonyms: getSynonyms(t, "removeImage"),
         automationSettings: null,
       },
@@ -1196,6 +1202,9 @@ export function useTranslatedToolCatalog(): TranslatedToolCatalog {
         subcategoryId: SubcategoryId.ADVANCED_FORMATTING,
         endpoints: ["scanner-effect"],
         synonyms: getSynonyms(t, "scannerEffect"),
+        // No frontend implementation yet (component is null), so it has no
+        // operationConfig to execute as an automation step.
+        supportsAutomate: false,
         automationSettings: null,
       },
 

frontend/editor/src/core/utils/toolIOCompat.test.ts

@@ -2,6 +2,7 @@
 
 import { readFileSync } from "node:fs";
 import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
 import { describe, expect, it } from "vitest";
 import {
   validateToolChain,
@@ -24,7 +25,9 @@ interface SharedCase {
 
 /** Shared with the backend and engine, so it lives at the repo root. */
 function casesFile(): string {
-  let current = dirname(new URL(import.meta.url).pathname);
+  // fileURLToPath, not URL.pathname: on Windows the latter yields "/C:/..." and
+  // resolving against it produces a "C:\C:\..." path that never matches.
+  let current = dirname(fileURLToPath(import.meta.url));
   for (let i = 0; i < 12; i++) {
     const candidate = resolve(current, "testing/tool-io-cases.json");
     try {

frontend/editor/src/core/utils/toolIOLabels.test.ts

@@ -1,5 +1,6 @@
 import { readFileSync } from "node:fs";
 import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
 import { describe, expect, it } from "vitest";
 import { TOOL_FORMATS, type ToolFormat } from "@app/types/toolIO";
 import {
@@ -9,7 +10,9 @@ import {
 
 /** The en-US `[toolFormat]` block, read straight from the locale file. */
 function toolFormatLabels(): Record<string, string> {
-  let current = dirname(new URL(import.meta.url).pathname);
+  // fileURLToPath, not URL.pathname: on Windows the latter yields "/C:/..." and
+  // resolving against it produces a "C:\C:\..." path that never matches.
+  let current = dirname(fileURLToPath(import.meta.url));
   for (let i = 0; i < 12; i++) {
     try {
       const toml = readFileSync(