The complete `build_timeseries.py` (277 lines) is identical to `/home/dev/research_loop/production/AMZN/build_timeseries.py` — verified by validator `build_timeseries regenerates 9 timeseries rows`. Key behaviors:

- Rolls up FY2026 `capex_guidance` vintages from `forecast_vintage.csv`
- `GUIDANCE_ORIGIN_QUARTER=FY2025-FQ4`; original/latest guidance $200B from first FY2026 vintage
- GW columns blank; capex proxy columns populated
- Generates SVG `company_gw_chart.html` with quarterly line + FY2024 annual diamond anchor