[Insights][R4][App] Add Compliance charts and chart eligibility rules #102809

Implement this section of the design doc: Add charts to the Compliance dashboard.

Description

Configure the Compliance dashboard's headline and supporting charts and apply the workspace eligibility rules for member charts.

• Add Violations over time, Top violations, Violations by submitter, and Violations by approver to INSIGHTS_DASHBOARD_SPECS, including each chart's query and the count metric.
• Add hasMultipleMembers and hasApprovalsEnabled helpers in insightsAccess.ts.
• Gate Violations by submitter on hasMultipleMembers.
• Gate Violations by approver on both hasMultipleMembers and hasApprovalsEnabled, using the existing per-chart isPolicyEligible mechanism.

Acceptance criteria

• The four chart specs render the corresponding backend results correctly using counts.
• Charts respond to the selected dashboard filters and comparisons.
• Submitter and approver chart visibility follows workspace eligibility.
• Include relevant eligibility tests and manual chart/filter/comparison regression steps.

Dependencies

• [Insights][R4][App] Add Compliance dashboard navigation and access rules #102807
• [Insights][R4][App] Support count metrics in charts and data tables #102808
• The existing Release 4 backend implementation issue.