feat(resolvemcp): add hook system for model operations

* Implement hooks for CRUD operations: before/after handle, read, create, update, delete.
* Introduce HookContext and HookRegistry for managing hooks.
* Allow registration and execution of multiple hooks per operation.

feat(resolvemcp): implement MCP tools for CRUD operations
* Register tools for reading, creating, updating, and deleting records.
* Define tool arguments and handle requests with appropriate responses.
* Support for resource registration with metadata.

fix(restheadspec): enhance cursor handling for joins
* Improve cursor filter generation to support lateral joins.
* Update join alias extraction to handle lateral joins correctly.
* Ensure cursor filters do not contain empty comparisons.

test(restheadspec): add tests for cursor filters and join alias extraction
* Create tests for lateral join scenarios in cursor filter generation.
* Validate join alias extraction for various join types, including lateral joins.

pkg/restheadspec/cursor.go

@@ -93,12 +93,18 @@ func (opts *ExtendedRequestOptions) GetCursorFilter(
 		}
 
 		// Handle joins
-		if isJoin && expandJoins != nil {
-			if joinClause, ok := expandJoins[prefix]; ok {
-				jSQL, cRef := rewriteJoin(joinClause, tableName, prefix)
-				joinSQL = jSQL
-				cursorCol = cRef + "." + field
-				targetCol = prefix + "." + field
+		if isJoin {
+			if expandJoins != nil {
+				if joinClause, ok := expandJoins[prefix]; ok {
+					jSQL, cRef := rewriteJoin(joinClause, tableName, prefix)
+					joinSQL = jSQL
+					cursorCol = cRef + "." + field
+					targetCol = prefix + "." + field
+				}
+			}
+			if cursorCol == "" {
+				logger.Warn("Skipping cursor sort column %q: join alias %q not in expandJoins", col, prefix)
+				continue
 			}
 		}
 

pkg/restheadspec/cursor_test.go

@@ -278,6 +278,47 @@ func TestCleanSortField(t *testing.T) {
 	}
 }
 
+func TestGetCursorFilter_LateralJoin(t *testing.T) {
+	lateralJoin := "inner join lateral  (\nselect string_agg(a.name, '.') as sortorder\nfrom tree(account.rid_account) r\ninner join account a on a.id = r.id\n) fn on true"
+
+	opts := &ExtendedRequestOptions{
+		RequestOptions: common.RequestOptions{
+			Sort: []common.SortOption{
+				{Column: "fn.sortorder", Direction: "ASC"},
+			},
+		},
+	}
+	opts.CursorForward = "8975"
+
+	tableName := "core.account"
+	pkName := "rid_account"
+	// modelColumns does not contain "sortorder" - it's a lateral join computed column
+	modelColumns := []string{"rid_account", "description", "pastelno"}
+	expandJoins := map[string]string{"fn": lateralJoin}
+
+	filter, err := opts.GetCursorFilter(tableName, pkName, modelColumns, expandJoins)
+	if err != nil {
+		t.Fatalf("GetCursorFilter failed: %v", err)
+	}
+
+	t.Logf("Generated lateral cursor filter: %s", filter)
+
+	// Should contain the rewritten lateral join inside the EXISTS subquery
+	if !strings.Contains(filter, "cursor_select_fn") {
+		t.Errorf("Filter should reference cursor_select_fn alias, got: %s", filter)
+	}
+
+	// Should compare fn.sortorder values
+	if !strings.Contains(filter, "sortorder") {
+		t.Errorf("Filter should reference sortorder column, got: %s", filter)
+	}
+
+	// Should NOT contain empty comparison like "< "
+	if strings.Contains(filter, " <  ") || strings.Contains(filter, " >  ") {
+		t.Errorf("Filter should not contain empty comparison operators, got: %s", filter)
+	}
+}
+
 func TestBuildPriorityChain(t *testing.T) {
 	clauses := []string{
 		"cursor_select.priority > posts.priority",

pkg/restheadspec/handler.go

@@ -723,13 +723,15 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 		// Extract model columns for validation using the generic database function
 		modelColumns := reflection.GetModelColumns(model)
 
-		// Build expand joins map (if needed in future)
-		var expandJoins map[string]string
-		if len(options.Expand) > 0 {
-			expandJoins = make(map[string]string)
-			// TODO: Build actual JOIN SQL for each expand relation
-			// For now, pass empty map as joins are handled via Preload
+		// Build expand joins map: custom SQL joins are available in cursor subquery
+		expandJoins := make(map[string]string)
+		for _, joinClause := range options.CustomSQLJoin {
+			alias := extractJoinAlias(joinClause)
+			if alias != "" {
+				expandJoins[alias] = joinClause
+			}
 		}
+		// TODO: also add Expand relation JOINs when those are built as SQL rather than Preload
 
 		// Default sort to primary key when none provided
 		if len(options.Sort) == 0 {

pkg/restheadspec/headers.go

@@ -552,10 +552,8 @@ func (h *Handler) parseCustomSQLJoin(options *ExtendedRequestOptions, value stri
 //   - "LEFT JOIN departments d ON ..." -> "d"
 //   - "INNER JOIN users AS u ON ..." -> "u"
 //   - "JOIN roles r ON ..." -> "r"
+//   - "INNER JOIN LATERAL (...) fn ON true" -> "fn"
 func extractJoinAlias(joinClause string) string {
-	// Pattern: JOIN table_name [AS] alias ON ...
-	// We need to extract the alias (word before ON)
-
 	upperJoin := strings.ToUpper(joinClause)
 
 	// Find the "JOIN" keyword position
@@ -564,7 +562,20 @@ func extractJoinAlias(joinClause string) string {
 		return ""
 	}
 
-	// Find the "ON" keyword position
+	// Lateral joins: alias is the word after the closing ) and before ON
+	if strings.Contains(upperJoin, "LATERAL") {
+		lastClose := strings.LastIndex(joinClause, ")")
+		if lastClose != -1 {
+			words := strings.Fields(joinClause[lastClose+1:])
+			// words should be like ["fn", "on", "true"] or ["on", "true"]
+			if len(words) >= 1 && !strings.EqualFold(words[0], "on") {
+				return words[0]
+			}
+		}
+		return ""
+	}
+
+	// Regular joins: find the "ON" keyword position (first occurrence)
 	onIdx := strings.Index(upperJoin, " ON ")
 	if onIdx == -1 {
 		return ""

pkg/restheadspec/headers_test.go

@@ -142,6 +142,16 @@ func TestExtractJoinAlias(t *testing.T) {
 			joinClause: "LEFT JOIN departments",
 			expected:   "",
 		},
+		{
+			name:       "LATERAL join with alias",
+			joinClause: "inner join lateral (select sortorder from compute_fn(t.id)) fn on true",
+			expected:   "fn",
+		},
+		{
+			name: "LATERAL join with multiline subquery containing inner ON",
+			joinClause: "inner join lateral  (\nselect string_agg(a.name, '.') as sortorder\nfrom tree(t.id) r\ninner join account a on a.id = r.id\n) fn on true",
+			expected:   "fn",
+		},
 	}
 
 	for _, tt := range tests {