docs: Enforce use of DSS browser utility in coding standards

Add mandatory_utilities section requiring LocalBrowserStrategy for all
browser automation tasks. Never create ad-hoc Playwright scripts.

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

.knowledge/DSS_CORE.json

@@ -194,7 +194,21 @@
     "events": "No inline handlers, use data-action pattern",
     "accessibility": "WCAG 2.1 AA, semantic HTML, ARIA attributes",
     "state": "Context store for global, component state for local, no direct DOM manipulation",
-    "errors": "Use logger utility, structured error codes (E1xxx-E5xxx, S1xxx)"
+    "errors": "Use logger utility, structured error codes (E1xxx-E5xxx, S1xxx)",
+    "browser_automation": "MUST use LocalBrowserStrategy from dss-claude-plugin/strategies/local/browser.py - NEVER create ad-hoc Playwright scripts"
+  },
+
+  "mandatory_utilities": {
+    "browser_testing": {
+      "class": "LocalBrowserStrategy",
+      "path": "dss-claude-plugin/strategies/local/browser.py",
+      "capabilities": ["console_log_capture", "screenshot", "dom_snapshot", "accessibility_audit", "core_web_vitals"],
+      "rule": "ALWAYS use this class for any browser automation. Never create temporary Playwright scripts."
+    },
+    "logging": {
+      "module": "dss-claude-plugin/core/structured_logger.py",
+      "rule": "Use structured logging, never print() or console.log for debugging"
+    }
   },
 
   "error_codes": {