fix: simplify parser API - remove NewParserFromFields

Corrections based on code review:
1. Removed NewParserFromFields helper - single NewParser(model) API only
2. Updated all tests to use actual struct models instead of field slices
3. Tests now demonstrate proper usage: NewParser(StructModel{})
4. Clean API: NewParser(model, config...) - no field slice constructors

All tests passing with simplified API.

Author: claude

storage/search/lucene/parser.go

@@ -75,18 +75,7 @@ func NewParser(model any, config ...*ParserConfig) (*Parser, error) {
 		return nil, err
 	}
 
-	// Get config or use nil
-	var cfg *ParserConfig
-	if len(config) > 0 && config[0] != nil {
-		cfg = config[0]
-	}
-
-	return NewParserFromFields(fields, cfg), nil
-}
-
-// NewParserFromFields creates a parser from an explicit list of fields.
-// This is primarily used for testing. Production code should use NewParser().
-func NewParserFromFields(fields []FieldInfo, config *ParserConfig) *Parser {
+	// Build field map
 	fieldMap := make(map[string]FieldInfo, len(fields))
 	for _, f := range fields {
 		fieldMap[f.Name] = f
@@ -97,15 +86,16 @@ func NewParserFromFields(fields []FieldInfo, config *ParserConfig) *Parser {
 	maxDepth := DefaultMaxDepth
 	maxTerms := DefaultMaxTerms
 
-	if config != nil {
-		if config.MaxQueryLength > 0 {
-			maxQueryLength = config.MaxQueryLength
+	if len(config) > 0 && config[0] != nil {
+		cfg := config[0]
+		if cfg.MaxQueryLength > 0 {
+			maxQueryLength = cfg.MaxQueryLength
 		}
-		if config.MaxDepth > 0 {
-			maxDepth = config.MaxDepth
+		if cfg.MaxDepth > 0 {
+			maxDepth = cfg.MaxDepth
 		}
-		if config.MaxTerms > 0 {
-			maxTerms = config.MaxTerms
+		if cfg.MaxTerms > 0 {
+			maxTerms = cfg.MaxTerms
 		}
 	}
 
@@ -115,7 +105,7 @@ func NewParserFromFields(fields []FieldInfo, config *ParserConfig) *Parser {
 		MaxDepth:       maxDepth,
 		MaxTerms:       maxTerms,
 		fieldMap:       fieldMap,
-	}
+	}, nil
 }
 
 // extractFields uses reflection to extract field metadata from a struct.