Simplify: O2M batch, domain dedup, db.go split, constants

Performance:
- O2M formatO2MFields: N+1 → single batched query per O2M field
  (collect parent IDs, WHERE inverse IN (...), group by parent)

Code dedup:
- domain.go compileSimpleCondition: 80 lines → 12 lines by delegating
  to compileQualifiedCondition (eliminates duplicate operator handling)
- db.go SeedWithSetup: 170-line monolith → 5 focused sub-functions
  (seedCurrencyAndCountry, seedCompanyAndAdmin, seedJournalsAndSequences,
  seedChartOfAccounts, resetSequences)

Quality:
- Magic numbers (80, 200, 8) replaced with named constants
- Net -34 lines

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pkg/server/web_methods.go

@@ -7,6 +7,12 @@ import (
 	"odoo-go/pkg/orm"
 )
 
+const (
+	defaultWebSearchLimit  = 80
+	defaultO2MFetchLimit   = 200
+	defaultNameSearchLimit = 8
+)
+
 // handleWebSearchRead implements the web_search_read method.
 // Mirrors: odoo/addons/web/models/models.py web_search_read()
 // Returns {length: N, records: [...]} instead of just records.
@@ -39,7 +45,7 @@ func handleWebSearchRead(env *orm.Environment, model string, params CallKWParams
 
 	// Parse offset, limit, order
 	offset := 0
-	limit := 80
+	limit := defaultWebSearchLimit
 	order := ""
 	if v, ok := params.KW["offset"].(float64); ok {
 		offset = int(v)
@@ -178,6 +184,8 @@ func formatO2MFields(env *orm.Environment, modelName string, records []orm.Value
 			continue
 		}
 
+		// Collect all parent IDs from records
+		var parentIDs []int64
 		for _, rec := range records {
 			parentID, ok := rec["id"].(int64)
 			if !ok {
@@ -185,38 +193,58 @@ func formatO2MFields(env *orm.Environment, modelName string, records []orm.Value
 					parentID = int64(pid)
 				}
 			}
-			if parentID == 0 {
-				rec[fieldName] = []interface{}{}
-				continue
+			if parentID > 0 {
+				parentIDs = append(parentIDs, parentID)
 			}
+		}
 
-			// Search child records where inverse_field = parent_id
-			childRS := env.Model(comodel)
-			domain := orm.And(orm.Leaf(inverseField, "=", parentID))
-			found, err := childRS.Search(domain, orm.SearchOpts{Limit: 200})
-			if err != nil || found.IsEmpty() {
-				rec[fieldName] = []interface{}{}
-				continue
+		// Initialize all records with empty slices
+		for _, rec := range records {
+			rec[fieldName] = []interface{}{}
+		}
+
+		if len(parentIDs) == 0 {
+			continue
+		}
+
+		// Single batched search: WHERE inverse_field IN (all parent IDs)
+		childRS := env.Model(comodel)
+		domain := orm.And(orm.Leaf(inverseField, "in", parentIDs))
+		found, err := childRS.Search(domain, orm.SearchOpts{Limit: defaultO2MFetchLimit})
+		if err != nil || found.IsEmpty() {
+			continue
+		}
+
+		// Single batched read
+		childRecords, err := found.Read(childFields)
+		if err != nil {
+			continue
+		}
+
+		// Format child records (M2O fields, dates, nulls)
+		formatM2OFields(env, comodel, childRecords, subFieldsSpec)
+		formatDateFields(comodel, childRecords)
+		normalizeNullFields(comodel, childRecords)
+
+		// Group child records by their inverse field (parent ID)
+		grouped := make(map[int64][]interface{})
+		for _, cr := range childRecords {
+			if pid, ok := orm.ToRecordID(cr[inverseField]); ok && pid > 0 {
+				grouped[pid] = append(grouped[pid], cr)
 			}
+		}
 
-			// Read child records
-			childRecords, err := found.Read(childFields)
-			if err != nil {
-				rec[fieldName] = []interface{}{}
-				continue
+		// Assign grouped children to each parent record
+		for _, rec := range records {
+			parentID, ok := rec["id"].(int64)
+			if !ok {
+				if pid, ok := rec["id"].(int32); ok {
+					parentID = int64(pid)
+				}
 			}
-
-			// Format child records (M2O fields, dates, nulls)
-			formatM2OFields(env, comodel, childRecords, subFieldsSpec)
-			formatDateFields(comodel, childRecords)
-			normalizeNullFields(comodel, childRecords)
-
-			// Convert to []interface{} for JSON
-			lines := make([]interface{}, len(childRecords))
-			for i, cr := range childRecords {
-				lines[i] = cr
+			if children, ok := grouped[parentID]; ok {
+				rec[fieldName] = children
 			}
-			rec[fieldName] = lines
 		}
 	}
 }