UOW-007: Implement File Streaming for Large Template Processing

[andhijeannot]

Overview

Phase: 3 - Performance
Priority: Medium
Estimated Effort: 8-10 hours

Problem Description

Current implementation loads entire files into memory for template processing, causing issues with large templates and poor memory usage.

Acceptance Criteria

• Large files (>10MB) are processed using streaming
• Memory usage remains constant regardless of file size
• Binary files are streamed without loading into memory
• Progress indication for large operations
• Performance improvement of >50% for large templates

Files to Modify

• internal/generator/streaming.go (new file)
• internal/generator/generator.go (update to use streaming)
• internal/generator/streaming_test.go (new file)

See roadmap/phase3-performance/UOW-007-file-streaming.md for detailed implementation plan.