Update all translations (#7380)

# Description of Changes

Update all translations

---

## 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.

scripts/translations/auto_translate.py

@@ -10,6 +10,7 @@ import sys
 import argparse
 import os
 import subprocess
+from concurrent.futures import ThreadPoolExecutor
 from pathlib import Path
 import time
 
@@ -141,27 +142,39 @@ def extract_untranslated(language_code, batch_size=500, include_existing=False):
 
 
 def translate_batches(
-    batch_files, language_code, api_key, timeout=600, model="gpt-5.5"
+    batch_files, language_code, api_key, timeout=600, model="gpt-5.5", parallel=1
 ):
     """Translate all batch files using the given OpenAI model."""
     if not batch_files:
         return []
 
-    print(f"\n🤖 Translating {len(batch_files)} batches using {model}...")
+    total = len(batch_files)
+    print(f"\n🤖 Translating {total} batches using {model}...")
     print(f"Timeout: {timeout}s ({timeout // 60} minutes) per batch")
+    if parallel > 1:
+        print(f"Running up to {parallel} batches in parallel")
 
-    translated_files = []
+    def translate_one(numbered_batch):
+        i, batch_file = numbered_batch
+        translated_file = batch_file.replace(".json", "_translated.json")
 
-    for i, batch_file in enumerate(batch_files, 1):
-        print(f"\n[{i}/{len(batch_files)}] Translating {batch_file}...")
+        # Resume: an existing output means this batch is already paid for
+        if Path(translated_file).exists():
+            print(f"\n[{i}/{total}] ✓ {batch_file} already translated, skipping")
+            return translated_file
+
+        print(f"\n[{i}/{total}] Translating {batch_file}...")
 
         # Always pass API key since it's required
         cmd = f'python3 scripts/translations/batch_translator.py "{batch_file}" --language {language_code} --api-key "{api_key}" --model {model}'
 
-        # Run with timeout
-        result = subprocess.run(
-            cmd, shell=True, capture_output=True, text=True, timeout=timeout
-        )
+        try:
+            result = subprocess.run(
+                cmd, shell=True, capture_output=True, text=True, timeout=timeout
+            )
+        except subprocess.TimeoutExpired:
+            print(f"✗ Timed out after {timeout}s: {batch_file}", file=sys.stderr)
+            return None
 
         if result.stdout:
             print(result.stdout)
@@ -172,14 +185,27 @@ def translate_batches(
             print(f"✗ Failed to translate {batch_file}")
             return None
 
-        translated_file = batch_file.replace(".json", "_translated.json")
-        translated_files.append(translated_file)
+        return translated_file
 
-        # Small delay between batches
-        if i < len(batch_files):
-            time.sleep(1)
+    numbered = list(enumerate(batch_files, 1))
 
-    print(f"\n✓ All {len(batch_files)} batches translated successfully")
+    if parallel > 1:
+        with ThreadPoolExecutor(max_workers=parallel) as pool:
+            translated_files = list(pool.map(translate_one, numbered))
+    else:
+        translated_files = []
+        for i, numbered_batch in enumerate(numbered, 1):
+            translated_files.append(translate_one(numbered_batch))
+            # Small delay between batches
+            if i < total:
+                time.sleep(1)
+
+    if any(f is None for f in translated_files):
+        failed = sum(1 for f in translated_files if f is None)
+        print(f"\n✗ {failed}/{total} batches failed")
+        return None
+
+    print(f"\n✓ All {total} batches translated successfully")
     return translated_files
 
 
@@ -310,6 +336,12 @@ Examples:
         action="store_true",
         help="Also retranslate existing keys that match English (default: only translate missing keys)",
     )
+    parser.add_argument(
+        "--parallel",
+        type=int,
+        default=1,
+        help="Batches to translate concurrently (default: 1 = sequential)",
+    )
     parser.add_argument(
         "--model",
         default="gpt-5.5",
@@ -349,7 +381,7 @@ Examples:
 
         # Step 2: Translate all batches
         translated_files = translate_batches(
-            batch_files, args.language, api_key, args.timeout, args.model
+            batch_files, args.language, api_key, args.timeout, args.model, args.parallel
         )
         if translated_files is None:
             sys.exit(1)