ARCHIVED [experiment over]: An AI agent built to do Ralph loops - plan mode for planning and ralph mode for implementing.

feat(context): ContextBuilder with compact structured format and AGENTS.md resolution master

Implement Task 7 from Phase 1d (Agent Runtime + Single-Agent Execution): - Add walkdir and glob dependencies to Cargo.toml for file system traversal - Create src/context/agents_md.rs with AGENTS.md resolution - Create src/context/mod.rs with ContextBuilder and ReadAgentsMdTool - Register ReadAgentsMdTool in v2 tool registry (create_v2_registry) - Add pub mod context to src/lib.rs Verifies P1d.AC5.1 and P1d.AC5.2 All tests passing (10 context tests + existing test suite). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>