fix(#2772): resolve four discuss-phase text inconsistencies (dead MAX_PASSES read, gate-prompts drift, circular auto_advance, answer_validation drift) (#2886)

* test(#2772): structural guards for the four discuss-phase text inconsistencies

* fix(#2772): resolve four discuss-phase text inconsistencies

1. auto.md: remove the dead MAX_PASSES/max_discuss_passes config read (contradicted
   the mandated single-pass rule + wasted a shim invocation per auto run).
2. gate-prompts.md: context-handling options now match the actual check_existing flow
   (Update it | View it | Skip, not Overwrite|Append|Cancel); gray-area-option no longer
   mandates 'Let Claude decide' (contradicts discuss-phase.md's no-cop-out rule).
3. discuss-phase.md: auto_advance fallback ends the workflow instead of routing back to
   the already-run confirm_creation step (circular).
4. discuss-phase-assumptions.md: re-sync answer_validation to the parent canonical block
   (had drifted — lost the 'Other' empty-text branch).

* chore(#2772): changeset fragment

* fix+test(#2772): also fix the assumptions auto_advance circularity (review minor 1) + add positive test anchors (review minor 2)

The sibling discuss-phase-assumptions.md had the identical auto_advance→confirm_creation
circularity; fix it the same way (end the workflow). Add positive anchors to both
auto_advance tests so a re-phrased regression can't slip past. File #2885 for the dead
max_discuss_passes config still advertised in settings/registry/docs (review minor 3).

* fix(#2772): keep discuss-phase.md under the 32000B #717 cap + ack assumptions growth

The auto_advance fixes + the assumptions answer_validation re-sync grew both files
past the emitted-attribution gate (and discuss-phase.md past the #717 32000B cap).
Condense the auto_advance prose in both files (discuss-phase.md now net -11, under
cap; auto.md already net -4650 from the MAX_PASSES shim removal). Add
discuss-phase-assumptions.md to tests/emitted-drift-ack.json for its residual +220
(answer_validation re-sync + auto_advance fix).

* chore(#2772): backfill changeset PR number (2886)

---------

Co-authored-by: Test <test@example.com>

tests/emitted-drift-ack.json

@@ -3,6 +3,9 @@
   "paths": {
     "plan-phase.md": {
       "reason": "#2770: decision-coverage gate recomputes CONTEXT_PATH in-block + guards the empty-glob case (handler now fails closed on empty arg). Net growth kept under the ADR-857 size cap by condensing adjacent §13a prose/JSON; the residual +89 bytes are the irreducible glob+guard logic."
+    },
+    "discuss-phase-assumptions.md": {
+      "reason": "#2772: re-synced <answer_validation> to the parent canonical block (had drifted — lost the 'Other' empty-text branch) + fixed the auto_advance→confirm_creation circularity (end the workflow). discuss-phase.md is net -11 (condensed); auto.md shrank -4650 (removed a dead MAX_PASSES resolver shim)."
     }
   }
 }

tests/issue-2772-discuss-phase-text-inconsistencies.test.cjs

@@ -0,0 +1,59 @@
+// allow-test-rule: structural-implementation-guard (#2772)
+'use strict';
+
+// Regression guard for #2772: four self-contained text inconsistencies in the
+// discuss-phase surface, each a literal-instruction hazard. The shipped markdown IS
+// the runtime contract, so structural inspection is the correct guard.
+
+const { test } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('fs');
+const path = require('path');
+
+const ROOT = path.join(__dirname, '..');
+const read = (rel) => fs.readFileSync(path.join(ROOT, rel), 'utf8');
+
+test('auto.md does not read the dead MAX_PASSES / max_discuss_passes config (#2772.1)', () => {
+  const src = read('gsd-core/workflows/discuss-phase/modes/auto.md');
+  assert.ok(/single pass/i.test(src), 'auto.md must still mandate the single-pass rule');
+  assert.ok(!/MAX_PASSES=/.test(src), 'auto.md must not read MAX_PASSES (dead config — single-pass rule governs) (#2772)');
+  assert.ok(!/max_discuss_passes/.test(src), 'auto.md must not reference max_discuss_passes (contradicts the single-pass rule) (#2772)');
+});
+
+test('gate-prompts context-handling matches the actual check_existing options (#2772.2)', () => {
+  const src = read('gsd-core/references/gate-prompts.md');
+  const ctx = src.slice(src.indexOf('## Pattern: context-handling'), src.indexOf('## Pattern: gray-area-option'));
+  assert.ok(/Update it \| View it \| Skip/.test(ctx), 'context-handling options must be "Update it | View it | Skip" (the actual check_existing flow) (#2772)');
+  assert.ok(!/Overwrite \| Append \| Cancel/.test(ctx), 'context-handling must NOT document the obsolete "Overwrite | Append | Cancel" (#2772)');
+});
+
+test('gate-prompts gray-area-option does not mandate "Let Claude decide" (#2772.2)', () => {
+  const src = read('gsd-core/references/gate-prompts.md');
+  const gray = src.slice(src.indexOf('## Pattern: gray-area-option'));
+  assert.ok(!/Always include "Let Claude decide"/i.test(gray), 'gray-area-option must NOT mandate "Let Claude decide" — it contradicts discuss-phase.md:353 ("Do NOT include a skip or you decide option") (#2772)');
+});
+
+test('discuss-phase auto_advance fallback ends the workflow, not routes back to confirm_creation (#2772.3)', () => {
+  const src = read('gsd-core/workflows/discuss-phase.md');
+  const step = src.slice(src.indexOf('<step name="auto_advance">'), src.indexOf('</step>', src.indexOf('<step name="auto_advance">')));
+  assert.ok(!/route to `confirm_creation`/.test(step), 'auto_advance fallback must not route back to confirm_creation (it already ran earlier in the step order — circular) (#2772)');
+  assert.ok(/end here|workflow is complete/i.test(step), 'auto_advance fallback must explicitly END the workflow (positive anchor — a re-phrased regression should not slip past) (#2772)');
+});
+
+test('discuss-phase-assumptions auto_advance fallback also ends the workflow (sibling of #2772.3)', () => {
+  const src = read('gsd-core/workflows/discuss-phase-assumptions.md');
+  const step = src.slice(src.indexOf('<step name="auto_advance">'), src.indexOf('</step>', src.indexOf('<step name="auto_advance">')));
+  assert.ok(!/Route to confirm_creation step/.test(step), 'assumptions auto_advance fallback must not route back to confirm_creation (same circularity as the parent) (#2772)');
+  assert.ok(/end here|workflow is complete/i.test(step), 'assumptions auto_advance fallback must explicitly END the workflow (#2772)');
+});
+
+test('discuss-phase-assumptions answer_validation matches the parent canonical content (#2772.4)', () => {
+  const parent = read('gsd-core/workflows/discuss-phase.md');
+  const assumptions = read('gsd-core/workflows/discuss-phase-assumptions.md');
+  // The parent's canonical answer_validation includes the "Other" empty-text branch.
+  const parentBlock = parent.slice(parent.indexOf('<answer_validation>'), parent.indexOf('</answer_validation>') + '</answer_validation>'.length);
+  const assumptionsBlock = assumptions.slice(assumptions.indexOf('<answer_validation>'), assumptions.indexOf('</answer_validation>') + '</answer_validation>'.length);
+  assert.ok(/"Other" with empty text/.test(assumptionsBlock), 'assumptions answer_validation must include the "Other" empty-text branch (was drifted) (#2772)');
+  // The two blocks must now agree on the empty-response handling.
+  assert.strictEqual(assumptionsBlock, parentBlock, 'discuss-phase-assumptions answer_validation must match the parent canonical block exactly (single source of truth) (#2772)');
+});