docs: remove status field from server.json examples (#575)

## Summary
- Remove the `status` field from all server.json examples in
documentation
- Remove the deprecated server example that was primarily about
demonstrating the status field
- Update example count validation from 13 to 12

## Context
The `status` field was removed from the server.json schema in commit
b21c6f5 (#562). This PR cleans up the documentation to reflect that
change.

## Why didn't tests catch this?
The schema validation didn't catch the invalid `status` field because
the JSON schema doesn't have `additionalProperties: false` set. This
means the schema allows arbitrary additional properties by default.

## Test plan
- [x] All validation checks pass (`make check`)
- [x] Example count updated to match the new total (12 examples)

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

Co-authored-by: Claude <noreply@anthropic.com>

tools/validate-examples/main.go

@@ -18,9 +18,9 @@ import (
 )
 
 type validationTarget struct {
-	path           string
-	requireSchema  bool
-	expectedCount  *int
+	path          string
+	requireSchema bool
+	expectedCount *int
 }
 
 func main() {
@@ -33,7 +33,7 @@ func main() {
 
 func runValidation() error {
 	// Define what we validate and how
-	expectedServerJSONCount := 13
+	expectedServerJSONCount := 12
 	targets := []validationTarget{
 		{
 			path:          filepath.Join("docs", "reference", "server-json", "generic-server-json.md"),
@@ -227,4 +227,4 @@ func compileSchema(path string) (*jsonschema.Schema, error) {
 	}
 
 	return compiler.Compile(path)
-}
+}