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-agents.test.ts

@@ -16,7 +16,7 @@ import {
 	type ToolCall,
 } from "@earendil-works/pi-ai";
 import type { PiEngine } from "../src/agent/models.ts";
-import { createPracticeAgents, renderChains, renderPreviousProblems } from "../src/agent/subagents/practice.ts";
+import { createPracticeAgents, renderChains, renderParams, renderPreviousProblems } from "../src/agent/subagents/practice.ts";
 import { ModelsNotConfiguredError, ProviderKeyMissingError, type ProviderKeyMissing } from "../src/core/settings.ts";
 import type { PracticeParams, ReasoningChain } from "../src/core/contracts.ts";
 
@@ -31,7 +31,7 @@ const chains: ReasoningChain[] = [
 	{ id: "n3", premises: ["n1"], conclusion: "n3" },
 	{ id: "n2", premises: [], conclusion: "n2" },
 ];
-const params: PracticeParams = { searchSolutionRatio: 0.7, cueDistance: 0.4, presentation: 0.6 };
+const params: PracticeParams = { ladderRung: 3, cueDistance: 2, presentation: "application" };
 
 function fauxEngine(steps: FauxResponseStep[]): PiEngine {
 	const faux = createFauxCore({});
@@ -70,6 +70,21 @@ function silentModel(): PiEngine {
 
 // ─── rendering ───────────────────────────────────────────────────────────────
 
+describe("renderParams — named levels, never a number", () => {
+	it("renders the exact named-level block", () => {
+		const out = renderParams(params);
+		assert.equal(
+			out,
+			[
+				"THE PARAMETERS",
+				"Ladder rung 3 — Composition: several steps, chained; the path is narrow but must be held and run.",
+				"Cue distance 2 — Far context: as far from the typical cue as recognition allows, the edge of the recognizable band — the proposition must still genuinely apply, and the learner must be able to find it by looking.",
+				'Presentation: Application — a concrete worldly affair — a case, episode, system, or story — in which the proposition\'s structure appears in the wild.',
+			].join("\n"),
+		);
+	});
+});
+
 describe("rendering (the agent-facing text)", () => {
 	it("renderChains: legend with names + statements, premises → conclusion, singletons marked", () => {
 		const text = renderChains(chains, propositions);