Add ESLint and Prettier, and close the node test gaps

Tooling:
- Prettier as the single formatting authority (110 columns, single quotes,
  measured against the existing style); Markdown excluded because table-cell
  padding turns the README glossary into 1000-character lines.
- Type-aware ESLint ending in eslint-config-prettier, so a rule always means
  "this is a bug", never "this looks different".
- .editorconfig and an `npm run check` that runs typecheck, lint, format and
  tests in one go.

Findings fixed on the first run: three more duplicate imports, four
String(unknown) calls (parameter types narrowed instead of casts), two dead
initialisers, two redundant casts, a console.log for a real error. Two
warnings were false here and are disabled with a reason in place.

Tests 132 -> 269:
- node-catalog.test.ts covers every node with a run(), with a guard that fails
  when a new node has no row.
- behavior-events.test.ts covers the ten event nodes through a running World,
  checking timing rather than existence.
- Input's state machine (press/release/releaseAll) is reachable without DOM
  events now; the DOM handlers are thin adapters.

Compare fell back to == without a configured operator although the schema
default is <; aligned.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/editor/inspector/nodeSection.ts

@@ -16,7 +16,11 @@ export function nodeSignature(project: Project, assetId: string, nodeId: string)
   const node = asset.graph.nodes.find((n) => n.id === nodeId);
   if (!node) return 'missing';
   const def = nodeDef(node.type);
-  const connected = def ? inlineInputs(def).filter((p) => edgesInto(asset.graph, node.id, p.key).length > 0).map((p) => p.key) : [];
+  const connected = def
+    ? inlineInputs(def)
+        .filter((p) => edgesInto(asset.graph, node.id, p.key).length > 0)
+        .map((p) => p.key)
+    : [];
   return `${node.type}|${connected.join(',')}|${asset.variables.map((v) => v.key).join(',')}`;
 }
 
@@ -35,7 +39,11 @@ export function buildNodeSection(host: InspectorHost, assetId: string, nodeId: s
   if (def.params.length > 0) addTitle(host, 'SETTINGS');
   for (const param of def.params) {
     const effective = resolveParamDef(host.state.project, param, asset);
-    const row = createFieldRow(effective, node.params[param.key] ?? effective.default, paramHandlers(host, assetId, nodeId, param.key));
+    const row = createFieldRow(
+      effective,
+      node.params[param.key] ?? effective.default,
+      paramHandlers(host, assetId, nodeId, param.key),
+    );
     host.fields.set(`param:${param.key}`, row);
     host.body.add(row.row);
   }
@@ -44,13 +52,22 @@ export function buildNodeSection(host: InspectorHost, assetId: string, nodeId: s
   if (free.length > 0) addTitle(host, 'INPUTS (unconnected)');
   for (const port of free) {
     const inline = inlineInputDef(port);
-    const row = createFieldRow(inline, node.params[port.key] ?? inline.default, paramHandlers(host, assetId, nodeId, port.key));
+    const row = createFieldRow(
+      inline,
+      node.params[port.key] ?? inline.default,
+      paramHandlers(host, assetId, nodeId, port.key),
+    );
     host.fields.set(`input:${port.key}`, row);
     host.body.add(row.row);
   }
 
   addGap(host);
-  host.body.add(new Button('Delete node', { variant: 'danger', onClick: () => host.state.execute(new RemoveNodeCommand(assetId, nodeId)) }));
+  host.body.add(
+    new Button('Delete node', {
+      variant: 'danger',
+      onClick: () => host.state.execute(new RemoveNodeCommand(assetId, nodeId)),
+    }),
+  );
 }
 
 /** Pushes the node's current params into the rows. False when the node is gone (rebuild). */
@@ -60,7 +77,10 @@ export function refreshNodeSection(host: InspectorHost, assetId: string, nodeId:
   if (!node || !def) return false;
   for (const [key, row] of host.fields) {
     const [scope, name] = key.split(':') as ['param' | 'input', string];
-    const fallback = scope === 'param' ? def.params.find((p) => p.key === name)?.default : inlineInputDef(def.inputs.find((p) => p.key === name)!).default;
+    const fallback =
+      scope === 'param'
+        ? def.params.find((p) => p.key === name)?.default
+        : inlineInputDef(def.inputs.find((p) => p.key === name)!).default;
     row.setValue(node.params[name] ?? fallback ?? '');
   }
   return true;
@@ -76,7 +96,12 @@ function resolveParamDef(project: Project, param: PropertyDef, asset: Asset): Pr
     return { ...param, options: asset.variables.map((v) => ({ value: v.key, label: v.key })) };
   }
   if (param.key === 'asset') {
-    return { ...param, options: project.assets.filter((a) => isPlaceableType(a.type)).map((a) => ({ value: a.id, label: `${a.name} (${a.type})` })) };
+    return {
+      ...param,
+      options: project.assets
+        .filter((a) => isPlaceableType(a.type))
+        .map((a) => ({ value: a.id, label: `${a.name} (${a.type})` })),
+    };
   }
   return param;
 }