Protocol guide

[marcosfrenkel]

Summary

Adds comprehensive user-facing documentation for the protocols subsystem, including lifecycle patterns, parameter handling, corrections/retries, and protocol composition. Also establishes documentation infrastructure for agents and domain context.

Changes

User Guide (docs/user_guide/protocols/)

• index.md — Quick start with 10-line runnable example
• parameters.md — Deep dive into parameter persistence and hardware translation
• operations.md — Operation lifecycle (measure → load_data → analyze → evaluate → correct), checks, and corrections
• protocols.md — Protocol composition patterns and report generation

Domain Documentation

• CONTEXT.md — Shared vocabulary for the protocols subsystem (parameter, operation, protocol, correction, etc.)
• docs/agents/ — New infrastructure for agent-facing docs (domain context, issue tracker, triage labels)
• AGENTS.md — Documented agent skills pattern with references to agent docs

Code

• select_platform() — New public API function for cleaner platform selection in examples
• gaussian_with_correction.py — Example operation demonstrating full lifecycle with correction handling
• Updated dummy parameters to match example

Verification

• ✅ All documentation builds (Sphinx)
• ✅ Code examples are runnable
• ✅ Links to API documentation are working
• ✅ Ruff checks pass

Notes

• No breaking changes to public API
• select_platform() exposes existing functionality with better ergonomics
• Documentation follows the existing Sphinx + MyST structure
• Agent docs follow the single-context layout (CONTEXT.md + docs/adr/)