Policy library index: map policies to accounts and processes

Create a policy library index for {company_name}.

Inputs:
- Existing policies list: {existing_policies}
- Chart of accounts and FS mapping: {coa_mapping}
- Key processes (revenue, AP, close): {processes}
- Policy owners and reviewers: {owners_reviewers}

Output:
1) Index table: Policy, Related accounts, Process, Owner, Reviewer, Last updated, Next review, Link/location.
2) Gaps (missing policies) based on accounts/processes.
3) Review cadence and change control workflow.

Make it practical for ongoing maintenance.