feat: OpenAI compatibility improvements & build fixes

- Fix hydration mismatches and initialization errors
- Add /v1/models endpoint for OpenAI clients
- Add Codex response translator (Responses → OpenAI)
- Fix circular dependencies and PropTypes
- Add Material Symbols font and CSS fixes
- Update README with deployment guide

Co-merged from PR #18 (14/15 commits, skipped debug)

.vscode/settings.json

@@ -1,3 +1,8 @@
 {
-  "css.lint.unknownAtRules": "ignore"
+  "css.lint.unknownAtRules": "ignore",
+  "sonarlint.rules": {
+    "css:S4662": {
+      "level": "off"
+    }
+  }
 }