feat: add ce:review-beta with structured persona pipeline (#348)

plugins/compound-engineering/agents/review/schema-drift-detector.md

@@ -15,7 +15,7 @@ assistant: "I'll use the schema-drift-detector agent to verify the schema.rb onl
 Context: The PR has schema changes that look suspicious.
 user: "The schema.rb diff looks larger than expected"
 assistant: "Let me use the schema-drift-detector to identify which schema changes are unrelated to your PR's migrations"
-<commentary>Schema drift is common when developers run migrations from main while on a feature branch.</commentary>
+<commentary>Schema drift is common when developers run migrations from the default branch while on a feature branch.</commentary>
 </example>
 </examples>
 
@@ -24,10 +24,10 @@ You are a Schema Drift Detector. Your mission is to prevent accidental inclusion
 ## The Problem
 
 When developers work on feature branches, they often:
-1. Pull main and run `db:migrate` to stay current
+1. Pull the default/base branch and run `db:migrate` to stay current
 2. Switch back to their feature branch
 3. Run their new migration
-4. Commit the schema.rb - which now includes columns from main that aren't in their PR
+4. Commit the schema.rb - which now includes columns from the base branch that aren't in their PR
 
 This pollutes PRs with unrelated changes and can cause merge conflicts or confusion.
 
@@ -35,19 +35,21 @@ This pollutes PRs with unrelated changes and can cause merge conflicts or confus
 
 ### Step 1: Identify Migrations in the PR
 
+Use the reviewed PR's resolved base branch from the caller context. The caller should pass it explicitly (shown here as `<base>`). Never assume `main`.
+
 ```bash
 # List all migration files changed in the PR
-git diff main --name-only -- db/migrate/
+git diff <base> --name-only -- db/migrate/
 
 # Get the migration version numbers
-git diff main --name-only -- db/migrate/ | grep -oE '[0-9]{14}'
+git diff <base> --name-only -- db/migrate/ | grep -oE '[0-9]{14}'
 ```
 
 ### Step 2: Analyze Schema Changes
 
 ```bash
 # Show all schema.rb changes
-git diff main -- db/schema.rb
+git diff <base> -- db/schema.rb
 ```
 
 ### Step 3: Cross-Reference
@@ -98,12 +100,12 @@ For each change in schema.rb, verify it corresponds to a migration in the PR:
 ## How to Fix Schema Drift
 
 ```bash
-# Option 1: Reset schema to main and re-run only PR migrations
-git checkout main -- db/schema.rb
+# Option 1: Reset schema to the PR base branch and re-run only PR migrations
+git checkout <base> -- db/schema.rb
 bin/rails db:migrate
 
 # Option 2: If local DB has extra migrations, reset and only update version
-git checkout main -- db/schema.rb
+git checkout <base> -- db/schema.rb
 # Manually edit the version line to match PR's migration
 ```
 
@@ -140,7 +142,7 @@ Unrelated schema changes found:
    - `index_users_on_complimentary_access`
 
 **Action Required:**
-Run `git checkout main -- db/schema.rb` and then `bin/rails db:migrate`
+Run `git checkout <base> -- db/schema.rb` and then `bin/rails db:migrate`
 to regenerate schema with only PR-related changes.
 ```