practice — discretized parameter axes: named levels, never a number (owner-approved 2026-09-29)

Contracts: LadderRung 0-4, CueDistance 0-2, Presentation theory|
application; PracticeParams carries the three named levels. Doc
comments hold the three definition tables verbatim (rung names +
definitions from the ladder doctrine; cue levels; presentation
levels).

Core: LADDER_RUNGS/CUE_LEVELS/PRESENTATIONS tables in src/core/
practice.ts (definitions verbatim) — ONE source spoken by the agents'
prompts, the dialog's stepped controls, and the exam header; core
barrel re-exports practice.ts (pure domain, browser-safe).

Agents: Part I's ladder intro now 'five rungs, numbered; the request
arrives as a rung' with bullets numbered 0-4 (definitions untouched);
Part III's parameters block replaced with the named-level doctrine
(rung = exact class, no continuum; cue counts lesson examples AND
previous problems' situations; presentation dresses, never changes);
partitioner's RESPECT THE PARAMETERS replaced (low rungs = many small
assignments, high = larger; far cue makes confusables-together MORE
important; presentation does not shape the partition). renderParams
outputs the exact named-level block. Anchor/0..1 language swept dead.

Service + store: strict union validation — floats between levels,
out-of-range, wrong strings, legacy dial shapes all 400 at the API
and fail isProblemSet (legacy sets skipped from lists; no migration —
data/practice is disposable scratch, owner wipes before testing).

UI: dialog = 5-detent ladder slider + 3-detent cue slider (each shows
the level NAME + one-line definition) + Theory|Application segmented
toggle; defaults rung 2 / cue 1 / theory; Create posts the new shape.
Exam header gains the levels line ('Direct exercise · Adjacent
context · Theory').

Tests: renderParams exact-block pin; strict-validation pins (new
tests/practice-service.test.ts — bad unions 400, legacy shape 400);
store pins (legacy floats + 2.5 rung fail); render pins (detents +
names + definitions, defaults, detent-swap, toggle active segment,
levels line); every params fixture moved off floats. 1138/1138, tsc
0, lint 0, build 0.

Docs: architecture.md — discretization paragraph (compact tables,
named-level invocation, defaults, one-table source), UI mentions;
README axes sentence.

tests/practice-store.test.ts

@@ -24,7 +24,7 @@ afterEach(() => {
 const init = (over: Partial<Omit<ProblemSet, "id">> = {}): Omit<ProblemSet, "id"> => ({
 	title: "Libertarianism — session practice",
 	createdAt: "2026-09-29T12:00:00.000Z",
-	params: { searchSolutionRatio: 0.7, cueDistance: 0.4, presentation: 0.6 },
+	params: { ladderRung: 2, cueDistance: 1, presentation: "theory" },
 	nodeIds: ["n_a", "n_b", "n_c"],
 	propositions: {
 		n_a: { name: "Self-ownership", statement: "Each person owns themself." },
@@ -122,6 +122,11 @@ describe("isProblemSet", () => {
 		assert.ok(!isProblemSet({}));
 		assert.ok(!isProblemSet({ ...init(), id: "xx_1" }));
 		assert.ok(!isProblemSet({ ...init(), params: { searchSolutionRatio: "high" } }));
+	// Legacy float-params sets fail the named-level unions and are
+	// skipped from lists (owner, 2026-09-29: no migration — data/practice
+	// is wiped before testing).
+	assert.ok(!isProblemSet({ ...init(), id: "ps_ok", params: { searchSolutionRatio: 0.7, cueDistance: 0.4, presentation: 0.6 } }));
+	assert.ok(!isProblemSet({ ...init(), id: "ps_ok2", params: { ladderRung: 2.5, cueDistance: 1, presentation: "theory" } }), "no floats between rungs");
 		assert.ok(!isProblemSet({ ...init(), chains: [{ id: "n_c", premises: "n_a", conclusion: "n_c" }] }));
 		assert.ok(!isProblemSet({ ...init(), propositions: { n_a: { name: "x" } } }));
 		assert.ok(!isProblemSet({ ...init(), status: "cooked" }));