test: Review Army — 14 diff-scope tests + 7 E2E tests

- test/diff-scope.test.ts: 14 tests for all 9 scope signals
- test/skill-e2e-review-army.test.ts: 7 E2E tests
  Gate: migration safety, N+1 detection, delivery audit,
        quality score, JSON findings
  Periodic: red team, consensus
- Updated gen-skill-docs tests for new review structure
- Added touchfile entries and tier classifications

test/fixtures/review-army-migration.sql

@@ -0,0 +1,5 @@
+-- Migration: Drop user email column
+-- WARNING: This migration is intentionally unsafe for testing
+ALTER TABLE users DROP COLUMN email;
+ALTER TABLE users DROP COLUMN phone_number;
+-- No backfill, no reversibility check, no data preservation

test/fixtures/review-army-n-plus-one.rb

@@ -0,0 +1,12 @@
+# N+1 query example — intentionally bad for testing
+class PostsController
+  def index
+    @posts = Post.all
+    @posts.each do |post|
+      # N+1: queries Author table for every post
+      puts post.author.name
+      # N+1: queries Comments table for every post
+      puts post.comments.count
+    end
+  end
+end