feat(TRUEREF-0013): implement trueref.json config file support

- Lenient parser for trueref.json and context7.json (trueref.json takes precedence)
- Validates folders, excludeFolders, excludeFiles, rules, previousVersions
- Stores config in repository_configs table
- JSON Schema served at GET /api/v1/schema/trueref-config.json for IDE validation
- Rules injected at top of every query-docs response

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/api/v1/schema/trueref-config.json/+server.ts

@@ -0,0 +1,36 @@
+/**
+ * GET /api/v1/schema/trueref-config.json
+ *
+ * Returns the JSON Schema for the trueref.json repository configuration file.
+ * IDE tooling (VS Code, JetBrains, etc.) can reference this URL in the
+ * `$schema` field of a trueref.json file to get autocomplete and validation.
+ *
+ * Example trueref.json with schema reference:
+ *   {
+ *     "$schema": "http://localhost:5173/api/v1/schema/trueref-config.json",
+ *     "projectTitle": "My Library",
+ *     "rules": ["Always use named imports"]
+ *   }
+ */
+
+import type { RequestHandler } from './$types';
+import schema from '$lib/server/config/trueref-config.json' assert { type: 'json' };
+import { CORS_HEADERS } from '$lib/server/api/formatters';
+
+export const GET: RequestHandler = () => {
+	return new Response(JSON.stringify(schema, null, 2), {
+		status: 200,
+		headers: {
+			'Content-Type': 'application/schema+json',
+			'Cache-Control': 'public, max-age=3600',
+			...CORS_HEADERS
+		}
+	});
+};
+
+export const OPTIONS: RequestHandler = () => {
+	return new Response(null, {
+		status: 204,
+		headers: CORS_HEADERS
+	});
+};