Initialize Sift

Follow this contract in order. Resolve the project root first. Materialization is the only write, and it is idempotent.

Identity pin

The installable name must match the directory that holds this skill. The line below is machine-read by tests/static/skill-prose-pins.test.sh; its target ends in /, so the test looks for the construct in that directory's SKILL.md front matter.

@PIN: src/skills/sift-init/ name: sift-init

1. Resolve the root and inspect the tree

Input. Start from the canonicalized $PWD. SIFT_ROOT=/path overrides the walk. Resolve the gate script's absolute path once and reuse it.