Add spec page and schemas.ts entry for context/name

Add name.mdx doc page following the pattern of sibling context
pages (remark, frame, etc.). Register the schema ID in schemas.ts
so the spec site links to the new page.

Author: gnidan

packages/web/spec/program/context/name.mdx

@@ -0,0 +1,16 @@
+---
+sidebar_position: 6
+---
+
+import SchemaViewer from "@site/src/components/SchemaViewer";
+
+# Named contexts
+
+Contexts may include a `name` property for distinguishing them from
+other contexts. This is particularly useful inside `pick` alternatives,
+where several possible contexts may apply at a given point in execution
+and runtime information is needed to select which one is active.
+
+<SchemaViewer
+  schema={{ id: "schema:ethdebug/format/program/context/name" }}
+/>

packages/web/src/schemas.ts

@@ -224,7 +224,7 @@ const programSchemaIndex: SchemaIndex = {
     href: "/spec/program/context",
   },
 
-  ...["code", "variables", "remark", "pick", "gather", "frame"]
+  ...["name", "code", "variables", "remark", "pick", "gather", "frame"]
     .map((name) => ({
       [`schema:ethdebug/format/program/context/${name}`]: {
         href: `/spec/program/context/${name}`,