architecture.md is the behavior map: layering, service map, seam
pattern, and the loop — everything else defers to its owning tier.
- Seam narrations compress to two-to-four sentences plus links to the
RFC and type-catalog homes that carry the detail (turn-end variant
semantics -> session.md, derivation mapping -> session.md, StreamChunk
conventions -> llm-streaming.md + source).
- The MVP feature-to-mechanism checklist moves de-statused into the
extension cookbook as 'The feature -> mechanism map' — mechanisms
only, no implementation-status bolding to rot; the microkernel RFC's
proof-obligation pointer follows it.
- The layering diagram describes layers by family instead of
enumerating packages (the stale 'future plugins: hooks, compaction'
row is gone); the dependency rule defers to packages/README.md.
- The loop pseudocode, the three externally-cited anchors (the
vocabulary, event taxonomy, waterfall semantics), and the filename
are unchanged.
- Budget ratchet: docs/architecture.md 3897 -> 1800 (now 1,797 words);
the doc-tiers RFC's deferred list prunes the item this ships.