prompts: Voice + Accuracy become shared fragments — one law across every agent (round 13 part A)

- shared/10-voice.md (agent-neutral) + shared/15-accuracy.md (research-tool
  truth contract) compose for teacher, prober, AND practice
- PRACTICE_SHARED_FRAGMENTS grows beyond 40-formatting.md
- practice 00-base.md drops its stale near-copy ("You have no research tool
  here" was false since round 10); the solve-and-shortcut-hunt line folds
  into the problem paragraph
- teaching system-prompt.md slims (Voice/Accuracy sections removed)
- pins updated: practice-agents composition, prompt-overrides segment mirror

tests/practice-agents.test.ts

@@ -251,6 +251,20 @@ describe("practice prompt composition (own directory + the formatting appendix)"
 		assert.doesNotMatch(prompt, /predict/i);
 	});
 
+	it("the SHARED voice + accuracy compose (owner round 13): ONE law across every agent, and the stale line is dead", () => {
+		const prompt = composeInstructions("practice");
+		// accuracy: the shared chunk's research-tool reference (round 10 gave
+		// practice research — the old near-copy said "You have no research
+		// tool here", which was false)
+		assert.match(prompt, /one confidently-delivered hallucination poisons that/);
+		assert.match(prompt, /you have a `research` tool/);
+		assert.ok(!prompt.includes("no research tool here"), "the stale line is gone");
+		// the teacher composes the same shared chunks (one law)
+		const teacher = composeInstructions("teacher");
+		assert.match(teacher, /one confidently-delivered hallucination poisons that/);
+		assert.match(teacher, /Everything in this section deletes a default/);
+	});
+
 	it("the SHARED formatting guide composes (owner, 2026-10-04 late): LaTeX delimiters in every setting", () => {
 		const prompt = composeInstructions("practice");
 		// The delimiter law — practice must write \(...\)/\[...\] too.

tests/prompt-overrides.test.ts

@@ -178,8 +178,10 @@ describe("the source-derived segment list", () => {
 			[
 				"system-prompt.md",
 				"prober/10-probe-doctrine.md",
+				"shared/10-voice.md",
+				"shared/15-accuracy.md",
 				"shared/20-question-tools.md",
-			"shared/25-confidence.md",
+				"shared/25-confidence.md",
 				"shared/30-learner-files.md",
 				"shared/40-formatting.md",
 			],
@@ -196,11 +198,12 @@ describe("the source-derived segment list", () => {
 		// the shared fragments compose for BOTH agents, same path key.
 		assert.equal(teacher.some((s) => s.path === "shared/30-learner-files.md" && s.shared), true);
 		assert.equal(prober.some((s) => s.path === "shared/30-learner-files.md" && s.shared), true);
-		// The voice block (owner, interlude 2026-09-23) lives in the BASE now
-		// (moved out of shared/ 2026-09-27) — one base for both agents.
-		assert.equal(prober.some((s) => s.path === "shared/10-personality.md"), false);
-		assert.equal(teacher.some((s) => s.path === "shared/10-personality.md"), false);
-		assert.ok(prober[0].sourceText.includes("## Voice"), "the voice composes via the base");
+		// Voice + accuracy moved BACK to shared/ fragments (owner round 13,
+		// 2026-10-05): one law across every agent — including practice, whose
+		// near-copy had drifted stale ("You have no research tool here").
+		assert.equal(prober.some((s) => s.path === "shared/10-voice.md" && s.shared), true);
+		assert.equal(teacher.some((s) => s.path === "shared/10-voice.md" && s.shared), true);
+		assert.equal(prober.some((s) => s.path === "shared/15-accuracy.md" && s.shared), true);
 		// Tool MECHANICS are shared; question METHODOLOGY is phase-owned.
 		assert.equal(prober.some((s) => s.path.startsWith("teacher/")), false);
 		assert.equal(teacher.some((s) => s.path.startsWith("prober/")), false);