feat: add video OCR/ASR, DOCX/PDF export, input block and risk config updates

- Video pipeline: video file OCR via VLM plus audio track ASR, integrated
  into job_handlers with progress emit per phase. New media_utils.py for
  audio extraction from video files.
- Document export: richExport.js replaces inline docx builder; DOCX and PDF
  export buttons are now enabled in MilkdownEditor. File size limit raised to
  100 MB.
- Input block: new InputBlockCrepe.vue component with inputBlockPlugin.ts
  and inputBlock.js for custom user-input nodes in the editor.
- Risk config: added Vite dev server ports (5173) to CORS allowlist and
  increased OCR max input from 10 MB to 100 MB.
- TTS/ASR refactor: simplified tts_asr.py model loading and warmup logic.
- Test coverage: updated tests for llm, main endpoints, pro completions and
  web search modules.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/prompt.py

@@ -355,8 +355,8 @@ def build_completion_prompts(
     if preferences:
         if preferences.language and preferences.language != "auto":
             pref_info.append(f"Preferred language: {preferences.language}")
-        if preferences.currency and preferences.currency != "auto":
-            pref_info.append(f"Preferred currency: {preferences.currency}")
+        if preferences.country and preferences.country != "auto":
+            pref_info.append(f"Preferred country: {preferences.country}")
 
     preferences_instruction = "\n".join(pref_info)
     if preferences_instruction:
@@ -454,8 +454,8 @@ def build_pro_completion_prompts(
     if preferences:
         if preferences.language and preferences.language != "auto":
             pref_info.append(f"Preferred language: {preferences.language}")
-        if preferences.currency and preferences.currency != "auto":
-            pref_info.append(f"Preferred currency: {preferences.currency}")
+        if preferences.country and preferences.country != "auto":
+            pref_info.append(f"Preferred country: {preferences.country}")
         if preferences.timezone and preferences.timezone != "auto":
             pref_info.append(f"Preferred timezone: {preferences.timezone}")