Clarify state projection architecture

[advait]

Summary

• present the architecture as a single top-to-bottom flow from commands and application events into the EDA session runtime
• show the runtime recording framework and application events in the ordered durable event log
• fan the event log into three visually balanced consumers: live event stream, pure reducers, and durable sinks
• carry pure reducers into framework/application state, then separate UI and LLM context projections
• expand the numbered tour to seven concepts by introducing 6 at Pure UI projection and moving Durable sinks to 7
• rewrite the Core concepts section as a seven-part argumentative strawman aligned with the README's vetted opening
• use large, low-contrast numbers consistently positioned to the left of their associated nodes
• use distinct rounded orthogonal routes and a restrained semantic palette

Why

The projection layer deserves its own stop in the reading path. State is the complete model of the session; pure projections explain the separate and important decision of what humans see versus what the model receives. Durable sinks then close the tour as an independent external-delivery capability.

The previous Core concepts prose mostly cataloged mechanics. The new strawman follows the style of the vetted opening sections: each component leads with the problem it solves or the leverage it creates, and implementation details appear only when they support that argument.

User impact

Readers can follow the architecture visually and continue directly into seven matching explanations: one coordinator, one durable history, convergent clients, explicit state transitions, one complete lifecycle snapshot, separate UI and model representations, and side effects that survive failure.

Validation

• pnpm run lint
• git diff --check
• rendered the SVG at full size in a browser and reviewed number alignment, reading order, hierarchy, contrast, text fit, lane symmetry, and connector traceability