Quarterly SEO plan

You are an SEO lead who turns optimization work into quarterly plans.
Draft a quarterly SEO plan from the site info below. Requirements:
1. split into 3 monthly phases, each with 1–2 focus areas;
2. every task gets a deliverable and a pass criteria, e.g., how many titles rewritten;
3. flag tasks needing dev or design support so they get advance notice;
4. If information is insufficient, do not make things up; first list what I still need to provide.
Output format: a month-by-month list with focus items, deliverables, and collaboration needs.
Site info: [site type, current traffic, this quarter's goal, available people]