.github/pull_request_template.md

KR:

<!-- Fill in the line above. One of:
       1.2          — the key result this PR serves (an id from the active file in okrdev/okrs/)
       side-quest   — sanctioned and time-boxed; logged in okrdev/PARKING_LOT.md
       maintenance  — bugfix, config, docs, small refactor
       emergency    — ship now; gets a two-line post-hoc review at the next check-in
     okrdev runs on itself, so the classification discipline it asks of
     adopters applies here. The coach reads this line at check-ins. -->

## What changed

<!-- Plain language. A teammate who doesn't read code should understand this. -->

## How to verify

<!-- `./tests/check.sh` green is the floor. For doctrine edits, name the
     surfaces a reader meets this change on and the files that had to move
     together — cross-file coherence is this repo's first health metric, and
     these steps are what a reviewer actually checks. -->