Migrate All Docling Embedders to Microservice, Remove HF dependencies from core app

[JSv4]

Initial rewrite to move all docling parser code to microservice. Replace all instances of LlamaIndex HuggingFaceEmbedding with our custom OpenContractPipelineEmbedding.

[codecov]

Codecov Report

Attention: Patch coverage is 98.29684% with 7 lines in your changes missing coverage. Please review.

Project coverage is 90.13%. Comparing base (8d4152c) to head (4452d56).
Report is 44 commits behind head on main.

Files with missing lines	Patch %	Lines
opencontractserver/pipeline/base/base_component.py	93.33%	2 Missing ⚠️
...actserver/pipeline/thumbnailers/pdf_thumbnailer.py	80.00%	2 Missing ⚠️
opencontractserver/pipeline/base/thumbnailer.py	92.85%	1 Missing ⚠️
...ractserver/pipeline/parsers/docling_parser_rest.py	98.59%	1 Missing ⚠️
...ntractserver/tests/test_doc_parser_docling_rest.py	99.09%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #362      +/-   ##
==========================================
+ Coverage   89.96%   90.13%   +0.16%     
==========================================
  Files         280      282       +2     
  Lines       12816    12810       -6     
==========================================
+ Hits        11530    11546      +16     
+ Misses       1286     1264      -22     

Files with missing lines	Coverage Δ
opencontractserver/llms/agents.py	40.35% <ø> (ø)
opencontractserver/pipeline/base/embedder.py	95.65% <100.00%> (+2.79%)	⬆️
opencontractserver/pipeline/base/parser.py	90.12% <100.00%> (+0.93%)	⬆️
opencontractserver/pipeline/base/post_processor.py	95.23% <100.00%> (+3.57%)	⬆️
...er/pipeline/embedders/minn_modern_bert_embedder.py	95.34% <100.00%> (+0.54%)	⬆️
...tserver/pipeline/embedders/modern_bert_embedder.py	93.75% <100.00%> (+0.89%)	⬆️
...ipeline/embedders/sent_transformer_microservice.py	89.74% <100.00%> (+3.07%)	⬆️
...ntractserver/pipeline/parsers/nlm_ingest_parser.py	92.15% <100.00%> (+0.49%)	⬆️
...ncontractserver/pipeline/parsers/oc_text_parser.py	94.87% <100.00%> (+0.13%)	⬆️
...actserver/pipeline/post_processors/pdf_redactor.py	91.66% <100.00%> (+0.59%)	⬆️
... and 10 more

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