chore(cli): Add config schema (#6142)

So you can IDE LSP support / autocompletion

libs/cli/examples/graphs/langgraph.json

@@ -1,4 +1,5 @@
 {
+  "$schema": "https://langgra.ph/schema.json",
   "python_version": "3.12",
   "dependencies": [
     "langchain_community",

libs/cli/examples/graphs_reqs_a/langgraph.json

@@ -1,4 +1,5 @@
 {
+  "$schema": "https://langgra.ph/schema.json",
   "dependencies": [
     "."
   ],

libs/cli/examples/graphs_reqs_b/langgraph.json

@@ -1,4 +1,5 @@
 {
+  "$schema": "https://langgra.ph/schema.json",
   "dependencies": [
     "."
   ],

libs/cli/js-examples/langgraph.json

@@ -1,4 +1,5 @@
 {
+  "$schema": "https://langgra.ph/schema.json",
   "node_version": "20",
   "graphs": {
     "agent": "./src/agent/graph.ts:graph"

libs/cli/python-monorepo-example/apps/agent/langgraph.json

@@ -1,4 +1,5 @@
 {
+  "$schema": "https://langgra.ph/schema.json",
   "dependencies": [".", "../../libs/shared", "../../libs/common"],
   "graphs": {
     "agent": "./src/agent/graph.py:graph"

libs/langgraph/tests/example_app/langgraph.json

@@ -1,5 +1,5 @@
 {
-  "$schema": "https://raw.githubusercontent.com/langchain-ai/langgraph/refs/heads/main/libs/cli/schemas/schema.json",
+  "$schema": "https://langgra.ph/schema.json",
   "graphs": {
     "app": "tests/example_app/example_graph.py:app"
   },