feat(readers): add PaddleOCRAPIReader in llama-index-readers-paddle-ocr

[alialiaaa0712-cell]

Description

Enhances the existing llama-index-readers-paddle-ocr package :

PaddleOCRAPIReader (new class): A new reader that supports both image files (jpg/png/etc.) and PDF documents via the PaddleOCR official SDK. Key features:

• use_parse=False (default): calls ocr(), returns plain text per page
• use_parse=True + parse-capable model (PP-StructureV3, PaddleOCR-VL-*): calls parse_document(), returns Markdown text per page
• use_parse=True + OCR-only model: automatically falls back to ocr()
• Configurable model, use_doc_orientation_classify, use_doc_unwarping parameters
• True async support via AsyncPaddleOCRClient
• Input validation: model name checked against SDK enum, file existence checked before API call

New Package?

• Yes
• No

Version Bump?

• Yes
• No

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

• I added new unit tests to cover this change
• I believe this change is already covered by existing unit tests

All tests in tests/test_readers_paddle_ocr.py pass (45 tests total), covering:

• PaddleOCRAPIReader: model validation, options construction, parse vs OCR routing, fallback behavior, file-not-found handling, async load

Suggested Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added Google Colab support for the newly added notebooks.
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I ran uv run make format; uv run make lint to appease the lint gods

[alialiaaa0712-cell]

PTAL