How to read it. The human, automation and AI shares and the bottleneck heat are our illustrative estimates, not measurements [C]. Click any phase for its full story across all six eras, or open the micro view for every phase of one era on one page, and any mark for the evidence. Pre-2021 history is background, not part of the book's verified research. 2027 to 2030 is a scenario, the base case from chapter 19. The Intelligence view follows chapter 13's intelligence stack.