Add docstrings to all public functions in forge/core/

[dentity007]

What needs to be done

Add Google-style docstrings to all public functions in forge/core/ modules (qdrant_client.py, embeddings.py, nim_client.py, triton_client.py, sync.py, utils.py).

Why this matters

Good documentation helps new contributors understand the codebase and makes the project more approachable.

Where to look

• forge/core/qdrant_client.py
• forge/core/embeddings.py
• forge/core/nim_client.py
• forge/core/triton_client.py
• forge/core/sync.py

Acceptance criteria

• All public functions have docstrings with Args, Returns, and Raises sections
• Existing tests still pass