feat(templates): add optional Business Context section to PROJECT.md template (#756)

* feat(templates): add optional Business Context section to PROJECT.md template

Adds an optional `## Business Context` section (Customer, Revenue model,
Success metric, Strategy notes) between Core Value and Requirements, for
monetized or customer-facing projects. Optional by default — an HTML comment
tells non-business projects to delete it; capped at four one-line fields to
stay a constraint reference, not a business plan. The milestone evolution
review in complete-milestone.md checks it only when the section is present.

Refs #72

* chore(changeset): set pr number for #72 fragment

* test(#72): add source-text-is-the-product exemption marker

Addresses review Minor #1 on PR #756. The contract test reads the
PROJECT.md template and complete-milestone workflow .md files and
asserts on their content (the local/no-source-grep pattern). Those
.md files ARE the product surface, so this is a valid
source-text-is-the-product case. Add the explicit // allow-test-rule
marker per RULESET.TESTS.no-source-grep.exemption so intent is
audit-traceable before the rule promotes to error (#453).

---------

Co-authored-by: Tom Boucher <trekkie@nomorestars.com>

tests/enh-72-business-context.test.cjs

@@ -0,0 +1,96 @@
+// allow-test-rule: source-text-is-the-product
+// The PROJECT.md template + complete-milestone workflow .md ARE the product surface
+// the runtime loads; asserting on their text tests the deployed contract directly.
+/**
+ * Enhancement #72 — optional Business Context section in the PROJECT.md template.
+ *
+ * Contract tests over the product-text surfaces (template + milestone workflow .md):
+ * the template offers a Business Context section that is explicitly OPTIONAL, capped
+ * at the four approved one-line fields, and the milestone evolution review treats it
+ * as conditional so non-business projects that deleted it are never forced to review it.
+ */
+const { test, describe } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('fs');
+const path = require('path');
+
+const TEMPLATE = path.join(__dirname, '..', 'gsd-core', 'templates', 'project.md');
+const COMPLETE_MILESTONE = path.join(__dirname, '..', 'gsd-core', 'workflows', 'complete-milestone.md');
+
+function parseTemplateContract(content) {
+  const lines = content.split(/\r?\n/);
+  const lower = content.toLowerCase();
+  // The Business Context block lives between its heading and the next "## " heading.
+  const startIdx = lines.findIndex(l => l.trim() === '## Business Context');
+  let sectionBody = '';
+  if (startIdx !== -1) {
+    const rest = lines.slice(startIdx + 1);
+    const endOffset = rest.findIndex(l => l.startsWith('## '));
+    sectionBody = (endOffset === -1 ? rest : rest.slice(0, endOffset)).join('\n');
+  }
+  const fieldOf = (label) => new RegExp(`^- \\*\\*${label}\\*\\*:`, 'm').test(sectionBody);
+  return {
+    hasSection: startIdx !== -1,
+    // Optional-by-default: an HTML comment tells non-business projects to delete it.
+    hasOptionalMarker: /<!--\s*OPTIONAL/i.test(sectionBody) && /delete this section/i.test(sectionBody),
+    fields: {
+      customer: fieldOf('Customer'),
+      revenueModel: fieldOf('Revenue model'),
+      successMetric: fieldOf('Success metric'),
+      strategyNotes: fieldOf('Strategy notes'),
+    },
+    fieldCount: (sectionBody.match(/^- \*\*/gm) || []).length,
+    // Positioned between Core Value and Requirements.
+    orderedBetweenCoreValueAndRequirements:
+      lower.indexOf('## core value') < lower.indexOf('## business context') &&
+      lower.indexOf('## business context') < lower.indexOf('## requirements'),
+    hasGuidelinesEntry: /\*\*Business Context:\*\*/.test(content),
+  };
+}
+
+function parseMilestoneContract(content) {
+  const lower = content.toLowerCase();
+  const lines = content.split(/\r?\n/);
+  const reviewLine = lines.find(l =>
+    l.toLowerCase().includes('business context') &&
+    (l.toLowerCase().includes('if present') || l.toLowerCase().includes('only if')),
+  );
+  return {
+    mentionsBusinessContext: lower.includes('business context'),
+    hasConditionalReview: Boolean(reviewLine),
+  };
+}
+
+describe('enhancement #72 — Business Context template section', () => {
+  const tpl = parseTemplateContract(fs.readFileSync(TEMPLATE, 'utf-8'));
+
+  test('template includes a Business Context section', () => {
+    assert.ok(tpl.hasSection, 'template must contain a "## Business Context" section');
+  });
+
+  test('section is marked OPTIONAL with delete-for-non-business guidance', () => {
+    assert.ok(tpl.hasOptionalMarker, 'section must carry an OPTIONAL HTML comment telling non-business projects to delete it');
+  });
+
+  test('section carries exactly the four approved one-line fields', () => {
+    assert.ok(tpl.fields.customer, 'missing **Customer** field');
+    assert.ok(tpl.fields.revenueModel, 'missing **Revenue model** field');
+    assert.ok(tpl.fields.successMetric, 'missing **Success metric** field');
+    assert.ok(tpl.fields.strategyNotes, 'missing **Strategy notes** field');
+    assert.strictEqual(tpl.fieldCount, 4, 'section is capped at four fields (constraint reference, not a business plan)');
+  });
+
+  test('section is positioned between Core Value and Requirements', () => {
+    assert.ok(tpl.orderedBetweenCoreValueAndRequirements, 'Business Context must sit between Core Value and Requirements');
+  });
+
+  test('guidelines document the Business Context section', () => {
+    assert.ok(tpl.hasGuidelinesEntry, 'guidelines block must include a **Business Context:** entry');
+  });
+
+  test('milestone evolution reviews Business Context only when present', () => {
+    const ms = parseMilestoneContract(fs.readFileSync(COMPLETE_MILESTONE, 'utf-8'));
+    assert.ok(ms.mentionsBusinessContext, 'complete-milestone must mention Business Context in its review');
+    assert.ok(ms.hasConditionalReview, 'the Business Context milestone review must be conditional on the section being present');
+  });
+});