Azure OpenAI Embeddings

[tylersatre]

This adds Azure OpenAI endpoints as an option for embeddings. I did have a bit of help from Claude Code in getting this done, but in testing it out locally it's working as expected. I tested it out with:

claude mcp add claude-context-local \
    -e EMBEDDING_PROVIDER=AzureOpenAI \
    -e EMBEDDING_MODEL=text-embedding-3-large \
    -e CUSTOM_EXTENSIONS=".vue,.ts,.php" \
    -e AZURE_OPENAI_API_KEY=<MY KEY> \
    -e AZURE_OPENAI_ENDPOINT=https://<ENDPOINT NAME>.openai.azure.com \
    -e AZURE_OPENAI_DEPLOYMENT_NAME=text-embedding-3-large \
    -- pnpm --dir /Users/tyler/claude-context/packages/mcp start

[zc277584121]

@tylersatre thanks for this PR, and due to the other early PR having been merged, this one has conflicts with the master branch, could you please resolve it, thanks

[tylersatre]

@zc277584121 I've got the conflicts resolved!