chore: remove AI dev files from repo and clean up env config

- Remove .claude/, openspec/, AGENTS.md, CLAUDE.md from git tracking
- Simplify .env.example: remove unused path configs (use config.py defaults)
- Clean up .env for production: remove hardcoded secrets, use env var substitution
- Path configs now use sensible defaults from backend/app/core/config.py:
  - uploads -> backend/uploads/
  - storage -> backend/storage/
  - results -> backend/storage/results/

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.env.example

@@ -1,7 +1,10 @@
 # Tool_OCR - Environment Configuration Template
 # Copy this file to .env.local and fill in your actual values
+#
+# Note: Most path configurations have sensible defaults in config.py
+# Only override if you need custom paths
 
-# ===== Database Configuration =====
+# ===== Database Configuration (Required) =====
 MYSQL_HOST=your-mysql-host
 MYSQL_PORT=3306
 MYSQL_USER=your-username
@@ -15,12 +18,12 @@ BACKEND_PORT=8000
 FRONTEND_HOST=0.0.0.0
 FRONTEND_PORT=5173
 
-# Security (generate a random string for production)
+# Security (generate a random string for production: openssl rand -hex 32)
 SECRET_KEY=your-secret-key-here-please-change-this-to-random-string
 ALGORITHM=HS256
 ACCESS_TOKEN_EXPIRE_MINUTES=1440
 
-# ===== External Authentication Configuration =====
+# ===== External Authentication Configuration (Required) =====
 EXTERNAL_AUTH_API_URL=https://your-auth-api.example.com
 EXTERNAL_AUTH_ENDPOINT=/api/auth/login
 EXTERNAL_AUTH_TIMEOUT=30
@@ -46,61 +49,21 @@ GPU_DEVICE_ID=0
 # ===== File Upload Configuration =====
 MAX_UPLOAD_SIZE=52428800
 ALLOWED_EXTENSIONS=png,jpg,jpeg,pdf,bmp,tiff,doc,docx,ppt,pptx
-UPLOAD_DIR=./uploads
-TEMP_DIR=./uploads/temp
-PROCESSED_DIR=./uploads/processed
-IMAGES_DIR=./uploads/images
-
-# ===== Export Configuration =====
-STORAGE_DIR=./storage
-MARKDOWN_DIR=./storage/markdown
-JSON_DIR=./storage/json
-EXPORTS_DIR=./storage/exports
-
-# ===== PDF Generation Configuration =====
-# Linux: /usr/bin/pandoc, macOS: /opt/homebrew/bin/pandoc
-PANDOC_PATH=/usr/bin/pandoc
-# Linux: /usr/share/fonts, macOS: /System/Library/Fonts
-FONT_DIR=/usr/share/fonts
-PDF_PAGE_SIZE=A4
-PDF_MARGIN_TOP=20
-PDF_MARGIN_BOTTOM=20
-PDF_MARGIN_LEFT=20
-PDF_MARGIN_RIGHT=20
+# Path defaults to backend/uploads - only override if needed
+# UPLOAD_DIR=./uploads
 
 # ===== Translation Configuration (DIFY API) =====
-# Enable translation feature
 ENABLE_TRANSLATION=true
-# DIFY API base URL
 DIFY_BASE_URL=https://your-dify-instance.example.com/v1
-# DIFY API key (get from DIFY dashboard)
 DIFY_API_KEY=your-dify-api-key
-# API request timeout in seconds
 DIFY_TIMEOUT=120.0
-# Maximum retry attempts
 DIFY_MAX_RETRIES=3
-# Batch translation limits
 DIFY_MAX_BATCH_CHARS=5000
 DIFY_MAX_BATCH_ITEMS=20
 
-# ===== Background Tasks Configuration =====
-TASK_QUEUE_TYPE=memory
-# REDIS_URL=redis://localhost:6379/0
-
 # ===== CORS Configuration =====
 CORS_ORIGINS=http://localhost:5173,http://127.0.0.1:5173
 
 # ===== Logging Configuration =====
 LOG_LEVEL=INFO
-LOG_FILE=./logs/app.log
-
-# ===== Development & Testing Configuration =====
-# Debug font path for visualization scripts
-DEBUG_FONT_PATH=/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf
-# Demo documents directory for testing
-DEMO_DOCS_DIR=./demo_docs
-# E2E test API base URL
-E2E_API_BASE_URL=http://localhost:8000/api/v2
-# E2E test credentials (set in .env.local for security)
-# E2E_TEST_USER_EMAIL=test@example.com
-# E2E_TEST_USER_PASSWORD=testpassword
+# LOG_FILE defaults to backend/logs/app.log