add gitea sig header check, add Json errors, begin AppState

.devcontainer/devcontainer.json

@@ -14,7 +14,7 @@
     },
     "customizations": {
         "vscode": {
-            "extensions": ["rust-lang.rust-analyzer"],
+            "extensions": ["rust-lang.rust-analyzer", "tamasfe.even-better-toml", "fill-labs.dependi"],
             "settings": {
                 "[rust]": {
                     "editor.defaultFormatter": "rust-lang.rust-analyzer",