Fix Codex web run activity summaries

[laotoutou]

Summary

• recognize web__run, web_run, and web.run as Codex web activity
• summarize batched code-mode web arguments such as search queries and opened references
• reuse rollout summary external classification in Session Activity instead of maintaining duplicate rules

Tests

• node --import tsx --test src/harnesses/codex/rollout-activity-summary.test.ts src/harnesses/codex/session-activity.test.ts src/server/harnesses/codex/rollout-activity.test.ts
• npm test
• npm run typecheck
• npx eslint src/harnesses/codex/rollout-activity-summary.ts src/harnesses/codex/rollout-activity-summary.test.ts src/harnesses/codex/session-activity.ts src/harnesses/codex/session-activity.test.ts