fix(gen): small config scrubs — openclaw blobs to real files, setup host drift, dead artifacts

- The three openclaw markdown blobs hardcoded inside gen-skill-docs.ts (which
  silently reverted any hand edit to their tracked outputs on regen) move to
  openclaw/templates/*.md source files; output shasums byte-identical.
- setup's --host allowlists gain cursor + slate — both fully registered hosts
  with generated output, but './setup --host cursor' exited 1 because two
  hand-rolled lists in setup had drifted from hosts/index.ts.
- scripts/proactive-suggestions.json deleted: 31KB regenerated on every run,
  read by nobody (the catalog-trim design's reader was never built); its
  emitter and three determinism tests (which guaranteed a file nothing reads
  didn't churn) retired with stays-retired pins.
- claude/SKILL.md.tmpl deleted: a complete 8.9KB skill that never generated
  output (directory name collides with the host id 'claude'), in no registry.
  Recoverable from git if ever wanted under a non-colliding name.
- openclaw's frozen extraFields.version '0.15.2.0' stamp dropped;
  includeSkills: [] no-ops omitted (the generator treats [] as absent);
  llms.txt 55 -> 54 skills.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/skill-validation.test.ts

@@ -1733,13 +1733,6 @@ describe('Codex skill validation', () => {
     expect(fs.existsSync(path.join(AGENTS_DIR, 'gstack-codex', 'SKILL.md'))).toBe(false);
   });
 
-  test('/claude skill is external-host-only — no Claude-host variant', () => {
-    // Claude host should not get an outside-voice skill that shells into Claude.
-    expect(fs.existsSync(path.join(ROOT, 'claude', 'SKILL.md'))).toBe(false);
-    // Codex/external hosts should get the generated wrapper.
-    expect(fs.existsSync(path.join(AGENTS_DIR, 'gstack-claude', 'SKILL.md'))).toBe(true);
-  });
-
   test('Codex skill names follow gstack-{name} convention', () => {
     const codexDirs = fs.readdirSync(AGENTS_DIR);
     for (const dir of codexDirs) {