MR-5 — Direct push for small fixes; PR for checkpoints

PR ceremony for two-line CSS is waste. PR ceremony for a multi-file feature is a checkpoint you’ll thank yourself for.

The boundary is set per-project at bootstrap (Q7). Default for full-stack repos:

Direct push OK: single-file bug fix, doc tweak, CSS / styling patch, test stabilisation, dependency bump (non-breaking).
PR required: multi-file feature, schema change, contract change, invariant addition or change, anything touching auth or RLS, anything on critical path for an active milestone.

The reviewer subagent does not require a PR for direct-push-eligible changes. It does require a session-log entry from the implementer.