Task 305: Stats Refresh

Status: DONE

Description

Update stale stats in reports and validation tests after Tasks 302-304.

Changes needed:

• Task count: 302 → 304
• Commit count: 441+ → 443+
• TS tests: 2,221 → 2,225 (if stale in reports)
• Total tests: 2,825 → check actual
• Update ai-costs body text (302タスク → 304)
• Update tech-overview table
• Update article-content-validation.test.ts assertions