fix(docker): install anthropic package for Claude support

[Milofax]

Summary

The MCP server Docker image cannot use the Anthropic LLM provider because the anthropic package is not installed. It's defined as an optional dependency under [project.optional-dependencies].providers but the Dockerfile only runs uv sync --no-group dev.

Problem

When configuring llm.provider: anthropic in config.yaml, the server fails because AnthropicClient cannot be imported.

Solution

Install only the anthropic package directly instead of using --extra providers, which would pull in heavy dependencies like torch and transformers from other providers (Voyage, etc.).

# Install anthropic for Claude support (not in default deps)
RUN --mount=type=cache,target=/root/.cache/uv \
    uv pip install anthropic>=0.49.0

Alternatives Considered

• --extra providers: Rejected because it installs all providers including torch/transformers (~500MB+)
• Build argument for provider selection: More complex, could be future enhancement

Test Plan

• Built Docker image with this change
• Configured MCP server with llm.provider: anthropic
• Successfully processed episodes using Claude via Anthropic API

🤖 Generated with Claude Code

[Milofax]

Quick bump on this one — it's a small fix to install the anthropic package in the Docker image for Claude support. Ready for review whenever you get a chance!