Restore MCP tool discovery for modern clients

Prevent musl release builds from reusing incompatible cache artifacts

fix(ci): drop unsupported Intel macOS release target

fix(ci): use supported Intel macOS release runner

install: auto-configure MCP providers

ci: pin release runners by target arch

chore: close verse-mcp claude code epic

feat: add agent workflow library

feat: add scan policy and reload controls

feat: extract shared grounding engine

docs(README): add detailed explanation of MCP's purpose and functionality

fix(mcp_server): satisfy clippy in docs query

ci(release): refresh workspace release scaffold

feat(mcp_server): expand docs retrieval tools

chore: update AGENTS.md to use scope