docs/architecture.md: new §7 'Practice — strengthening, not assessment'
(purpose ruling + parked exam machinery; the chain bijection with
follows-edges, supports invisible, exactly-once partition; self-
contained sets frozen at creation; two-stage generation — partitioner,
one generator per problem with YOUR TARGET echo law + THE FULL SET
minimal-use doctrine, commit-before-pose, failure isolation, dedup
across sets; feedback-only grading; registry-not-JobRecords jobs
pattern and WHY — not chat-scoped, never wakes the teacher, boot
sweep; API + UI surfaces; three strong-pinned roles on the shared
runSubmitAgent seam). Sections 7-13 renumbered to 8-14; the §9
cross-ref in the deferred list updated. Cross-referenced enumerations
updated: §1 six-systems table + row, §2 layer count 25→28 routes,
§2.2 seven contract files + practice.ts, §3 PracticeStore port +
adapter + composition-root bullets + PORTSBOX, §4 six-systems heading
+ PRACTICE mermaid box + practice-request protocol, §6 practice-
territory sentence now points at the landed module, §10 observability
practice rows + abort kinds, §11 testing strata, §12 seam directory
row.
README.md: practice paragraph in Key mechanisms at the same grain
(feedback-only problem sets, partitioner/generator/grader, registry
jobs); the graph paragraph's 'assessment becomes practice-module
territory' forward-reference resolved to the landed module.
Docs-only — no code changes. 1129/1129, tsc 0, lint 0, build 0.