ci(formatting): Add Ruff and documentation automation

[harrison-lccc]

Summary

• Consolidate documentation tooling in the locked uv development environment
• Add Sphinx/AutoAPI Markdown generation and Confluence post-processing
• Add informational Interrogate coverage reporting through GitHub Actions
• Add deterministic formatter tests and shared Ruff VS Code settings

Validation

• uv lock --check
• uv sync --locked --group dev
• uv run --locked pytest — 44 passed
• Focused formatter tests — 4 passed
• uv run --locked ruff check . --statistics
• Sphinx Markdown build succeeds with 14 existing documentation warnings
• Interrogate reports 75.4% coverage with informational threshold 0

Closes #72