docs(voyage): bump v4.3.0 + update CLAUDE.md + README.md + CHANGELOG.md

Step 33 of v4.3 plan — Wave 8 docs (3-doc-niv mandate):

- package.json: version 4.2.0 -> 4.3.0
- CHANGELOG.md: v4.3.0 entry dated 2026-05-10 with Added/Changed/Fixed/
  Deferred-to-v4.4/Notes covering Wave 0-8 leveranser (dashboard-sentrisk
  layout, file://-loader 3 entry points, anchor-rendering modent, A11Y
  panel fra DS-primitives, screenshots-spor convention, DOMPurify ven-
  doring, voyage-scope DS-tokens, test pyramid Groups A-D, Playwright
  devDeps).
- CLAUDE.md: nytt 'Playground (v4.3)' avsnitt under Architecture som
  beskriver dashboard-modell, file-loader, anchor-rendering, A11Y panel,
  screenshots-spor, security hardening, og test pyramid.
- README.md: version badge 3.4.1 -> 4.3.0; '/trekrevise — Annotation
  playground' avsnitt utvidet med v4.3 rebuild-detaljer og pekere til
  playground/README.md + sc1-checklist-verification.md.

Test count: 705 pass / 0 fail / 2 skipped (npm test).
doc-consistency.test.mjs: 42/42 pass.

plugins/voyage/package.json

@@ -1,6 +1,6 @@
 {
   "name": "voyage",
-  "version": "4.2.0",
+  "version": "4.3.0",
   "description": "Voyage — brief, research, plan, execute, review, revise, continue. Contract-driven Claude Code pipeline + first marketplace playground.",
   "type": "module",
   "engines": {