# Session Funnel Analysis

Phase 72.5.2.3 adds `@v2/session-funnel-analysis`, the operational funnel
surface for the new-player path from tutorial through first purchase. The policy
is `v2-session-funnel-analysis-v1`.

`buildV2SessionFunnelAnalysisSurface` composes `@iris/analytics-funnel` to
analyze the ordered tutorial, first mission, open world, and first purchase
steps. It emits step entrants, conversion rates, drop-off rates, drop-off reason
counts, and chart-ready bars for dashboard rendering.

The service consumes hashed account identifiers (`accountIdHash`) and session
IDs. Output surfaces expose aggregate funnel and drop-off data only; raw account
IDs are not accepted or emitted.

## Operator Surface

Rendered UI should put the funnel chart and step table first: tutorial, first
mission, open world, and first purchase should remain visible as the canonical
sequence. Drop-off rate, conversion rate from previous step, and drop-off reason
breakdowns should be scannable without hiding the trend behind decorative
visuals.

Segment controls can switch acquisition cohort, platform, and time window when
those filters are available. Keep the first screen focused on the new-player
flow and the highest drop-off step.

## Verification

Targeted verification:

```bash
pnpm --filter @v2/session-funnel-analysis run typecheck
pnpm --filter @v2/session-funnel-analysis run test
python V2/ue/Tools/check-v2-session-funnel-analysis.py
python -m json.tool V2/ue/Build/Telemetry/v2-session-funnel-analysis.json
```