chore(markdown): restore main lint config

Author: drew

.markdownlint-cli2.jsonc

@@ -10,12 +10,7 @@
     ".opencode/**",
     ".github/**",
     "THIRD-PARTY-NOTICES/**",
-    "CLAUDE.md",
-    "target/**",
-    "e2e/rust/target/**",
-    "scripts/lint-mermaid/node_modules/**",
-    ".venv/**",
-    "artifacts/**"
+    "CLAUDE.md"
   ],
   "config": {
     "default": true,