Add ACP (AI Context Protocol) schemas to catalog (SchemaStore#5233)

Add three schema entries for the AI Context Protocol specification:
- ACP Cache File (.acp.cache.json) - indexed codebase metadata
- ACP Configuration File (.acp.config.json) - project settings
- ACP Variables File (.acp.vars.json) - reusable context variables

Schemas are self-hosted at https://acp-protocol.dev/schemas/v1/

Author: ddunnock

src/api/json/catalog.json

@@ -193,6 +193,24 @@
         "11.2.0": "https://www.schemastore.org/abc-supply-plan-11.2.0.json"
       }
     },
+    {
+      "name": "ACP Cache File",
+      "description": "AI Context Protocol cache file format for storing indexed codebase metadata",
+      "fileMatch": [".acp.cache.json"],
+      "url": "https://acp-protocol.dev/schemas/v1/cache.schema.json"
+    },
+    {
+      "name": "ACP Configuration File",
+      "description": "AI Context Protocol configuration file for project-level settings",
+      "fileMatch": [".acp.config.json"],
+      "url": "https://acp-protocol.dev/schemas/v1/config.schema.json"
+    },
+    {
+      "name": "ACP Variables File",
+      "description": "AI Context Protocol variables file for reusable context variables",
+      "fileMatch": [".acp.vars.json"],
+      "url": "https://acp-protocol.dev/schemas/v1/vars.schema.json"
+    },
     {
       "name": "AIConfig",
       "description": "AIConfig that is used to store generative AI prompts, models and model parameters",