refactor: Replace schema pattern test with SSE template validation example

Instead of adding a new test pattern (schema_pattern_test.go), add a
simple SSE transport example with template variables to the documentation
which gets validated by the existing validate-examples tool.

Changes:
- Add SSE remote transport example with {tenant_id} template variable
  to generic-server-json.md
- Update expectedServerJSONCount from 14 to 15 in validate-examples tool
- Remove internal/validators/schema_pattern_test.go (new test pattern)

This follows the existing testing patterns where schema validation
happens through documentation examples rather than dedicated unit tests.
The new SSE example proves that template variables work correctly with
the pattern validation added in the previous commit.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: tadasant

docs/reference/server-json/generic-server-json.md

@@ -701,6 +701,29 @@ This example demonstrates URL templating for remote servers, useful for multi-te
 
 Clients configure the tenant identifier, and the `{tenant_id}` variable in the URL gets replaced with the provided variable value to connect to the appropriate tenant endpoint (e.g., `https://anonymous.modelcontextprotocol.io/mcp/us-cell1` or `https://anonymous.modelcontextprotocol.io/mcp/emea-cell1`).
 
+The same URL templating works with SSE transport:
+
+```json
+{
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "name": "io.modelcontextprotocol.anonymous/events-server",
+  "description": "MCP server using SSE with tenant-specific endpoints",
+  "version": "1.0.0",
+  "remotes": [
+    {
+      "type": "sse",
+      "url": "https://events.anonymous.modelcontextprotocol.io/sse/{tenant_id}",
+      "variables": {
+        "tenant_id": {
+          "description": "Tenant identifier",
+          "isRequired": true
+        }
+      }
+    }
+  ]
+}
+```
+
 ### Local Server with URL Templating
 
 This example demonstrates URL templating for local/package servers, where variables reference parent Package arguments or environment variables:

internal/validators/schema_pattern_test.go

@@ -33,7 +33,7 @@ func main() {
 
 func runValidation() error {
 	// Define what we validate and how
-	expectedServerJSONCount := 14
+	expectedServerJSONCount := 15
 	targets := []validationTarget{
 		{
 			path:          filepath.Join("docs", "reference", "server-json", "generic-server-json.md"),