fix(workflow): offer recommendation instead of hard redirect for missing UI-SPEC.md (#2039)

* fix(workflow): offer recommendation instead of hard redirect when UI-SPEC.md missing

When plan-phase detects frontend indicators but no UI-SPEC.md, replace the
AskUserQuestion hard-exit block with an offer_next-style recommendation that
displays /gsd-ui-phase as the primary next step and /gsd-plan-phase --skip-ui
as the bypass option. Also registers --skip-ui as a parsed flag so it silently
bypasses the UI gate.

Closes #2011

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* ci: retrigger CI — resolve stale macOS check

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/plan-phase-ui-redirect.test.cjs

@@ -0,0 +1,51 @@
+'use strict';
+
+const { describe, test } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('fs');
+const path = require('path');
+
+describe('plan-phase UI-SPEC missing behavior', () => {
+  const workflowPath = path.join(
+    __dirname,
+    '..',
+    'get-shit-done',
+    'workflows',
+    'plan-phase.md'
+  );
+
+  test('workflow file exists', () => {
+    assert.ok(fs.existsSync(workflowPath), `Expected workflow file at ${workflowPath}`);
+  });
+
+  test('does NOT contain hard-blocking exit redirect to /gsd-ui-phase', () => {
+    const text = fs.readFileSync(workflowPath, 'utf8');
+    // The hard redirect pattern: AskUserQuestion option exits with "Run /gsd-ui-phase... Exit workflow."
+    // This is the pattern from line ~503 in the original file
+    const hardExitPattern = /Generate UI-SPEC first.*Exit workflow/s;
+    assert.ok(
+      !hardExitPattern.test(text),
+      'plan-phase.md must NOT contain a hard "Generate UI-SPEC first → Exit workflow" redirect. ' +
+      'It should offer a primary recommendation with --skip-ui bypass option instead.'
+    );
+  });
+
+  test('contains --skip-ui bypass option when UI-SPEC.md is missing', () => {
+    const text = fs.readFileSync(workflowPath, 'utf8');
+    assert.ok(
+      text.includes('--skip-ui'),
+      'plan-phase.md must include --skip-ui as a bypass option when UI-SPEC.md is missing'
+    );
+  });
+
+  test('contains a primary recommendation block for missing UI-SPEC', () => {
+    const text = fs.readFileSync(workflowPath, 'utf8');
+    const hasRecommendationPattern =
+      text.includes('Recommended next step') &&
+      text.includes('gsd-ui-phase');
+    assert.ok(
+      hasRecommendationPattern,
+      'plan-phase.md must include a "Recommended next step" recommendation for /gsd-ui-phase when UI-SPEC.md is missing'
+    );
+  });
+});