feat(office-hours): skill diet (GSTA-134 pilot 2)

Moves the Phase 3.5 Codex second opinion and the Phase 4.25 visual design
(designer mockups / HTML sketch) out of the eager SKILL.md into on-demand
sections behind STOP pointers; the CODEX_SECOND_OPINION, DESIGN_MOCKUP and
DESIGN_SKETCH resolvers are untouched. Claude-host SKILL.md 73,248 -> 43,885
bytes. skill-diet before/after (Opus, 9 tasks x 3): success 26/27 -> 27/27,
median tokens per successful run 170,197 -> 124,941; blind judge after 10,
before 5 of 15. YC pitch, flattery and promo text unchanged (sections
byte-identical to main).

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

test/design-printed-paths.test.ts

@@ -110,7 +110,7 @@ describe('design printed-paths tripwire', () => {
 
 describe('design generating flows', () => {
   const flows: Record<string, string[]> = {
-    'office-hours': ['office-hours/SKILL.md'],
+    'office-hours': ['office-hours/sections/visual-design.md'],
     'plan-design-review': ['plan-design-review/SKILL.md'],
     'design-consultation': ['design-consultation/sections/proposal-and-preview.md'],
     'design-shotgun': ['design-shotgun/SKILL.md'],

test/design-setup-probe.test.ts

@@ -105,7 +105,7 @@ describe('B4: DESIGN_READY requires a binary that starts', () => {
 
   test('office-hours visual exploration uses the same probe', () => {
     const w = world(HOSTS[0].root, 'kill -9 $$');
-    const r = run(fenceAfter(path.join(HOSTS[0].dir('office-hours'), 'SKILL.md'), '## Visual Design Exploration'), w);
+    const r = run(fenceAfter(path.join(HOSTS[0].dir('office-hours'), 'sections', 'visual-design.md'), '## Visual Design Exploration'), w);
     expect(r.stdout.trim()).toStartWith('DESIGN_NOT_AVAILABLE: ');
     expect(r.stdout).toContain('exited 137 (killed at launch');
   });

test/run-in-background-guidance.test.ts

@@ -332,7 +332,7 @@ const GENERATED_WITH_GUIDANCE = [
   'design-consultation/sections/proposal-and-preview.md',
   'design-review/SKILL.md',
   'document-release/sections/release-body.md',
-  'office-hours/SKILL.md',
+  'office-hours/sections/second-opinion.md',
   'office-hours/sections/design-and-handoff.md',
   'plan-ceo-review/SKILL.md',
   'plan-ceo-review/sections/review-sections.md',