[Code Quality] Consolidate 3 duplicated per-tool aggregate call stats structs in pkg/cli

[github-actions]

Description

The "per-tool aggregate call stats" concept is modeled three separate times under different naming conventions, all carrying the same call-count/size/duration/error fields.

Suggested Changes

• Apply the same base-struct treatment as the MCP-server-stats consolidation (companion issue): introduce a shared base for call-count, size, duration and error fields.
• Do this together with the MCP-server-stats work since they share call sites in the audit report generators.

Files Affected

• pkg/cli/audit_report.go:166 — ToolUsageInfo
• pkg/cli/audit_report.go:184 — MCPToolSummary
• pkg/cli/gateway_logs_types.go:97 — GatewayToolMetrics

Note: ToolUsageInfo may already be tracked for removal via #40803 in favor of workflow.ToolCallInfo — verify against that issue before duplicating scope, and prefer consolidating MCPToolSummary/GatewayToolMetrics around whichever canonical type wins.

Success Criteria

• Single canonical base/type for per-tool aggregate stats used across audit and gateway reports
• No behavior change in generated reports
• All existing tests pass

Source

Extracted from Typist: Go Type Consistency Analysis discussion #50544

Priority

Medium-High - companion to MCP-server-stats consolidation; estimated 2-3 hours

🔍 Task mining by Discussion Task Miner - Code Quality Improvement Agent · auto · 44.7 AIC · ⌖ 3.06 AIC · ⊞ 10.3K · ◷

• expires on Aug 6, 2026, 11:12 AM UTC-08:00