feat: release version 2.1.0

[ninedter]

Summary

• add a persisted 10K to 1M model context-window control with a conservative 50% input budget
• add No context window limit mode, disabling the slider and sending all sanitized evidence in one request
• apply the selected context policy across LM Studio, OpenAI, Anthropic, foreground, and background report paths
• improve report grounding, case and chart scalability, API audit attribution, Docker image construction, and Streamlit compatibility
• synchronize package, API, English, and Traditional Chinese release documentation at 2.1.0

Why 2.1.0

This is a backward-compatible minor release: it adds user-facing LLM capabilities and meaningful runtime improvements without intentionally removing API routes, changing authentication contracts, or requiring a destructive data migration. Existing installs default to a 32K-token window with a 50% input budget, and SQLite migrations remain automatic.

Verification

• make verify: 1,034 passed, 22 skipped
• make docker-verify: 1,034 passed, 22 skipped