AGENTS.md gains a non-negotiable session start protocol that
forces reading the context files and checking the current
branch before any edits. shared.md gains a pre-commit
checklist covering branch/scope, code rules, mechanical
checks, and commit metadata. both additions exist because
this branch's history shows what happens when the rules are
treated as background information rather than active
checklists.
Forcing every call site to be explicit eliminates a class of bugs where an unintended default silently slips through. Codifies the convention already established by prior commits (cd40483, b41652a, 8eb0f23).
