Decompose the single docs/how-to.md into an indexed 5-chapter guide under
docs/how-to/: README (index/pitch/teaser/TOC), 01 the company, 02 it starts
with you, 03 the cells build it, 04 the last call and the loop. Image/video
paths rewritten to ../, inter-chapter nav added, the Prompter-build screenshots
preserved. Adds a new chapter 05 — the business workflow: the charter, the
Cockpit, the Secretary, and the web-research / strategy-engine config toggles,
with the end-to-end 'feel it' walkthrough. README links repointed to
docs/how-to/README.md. All image links verified; reflow-check clean.
