feat: default Location tree and Asset Categories

Location fixture: "All Locations" group with Head Office, Branch Office and
Warehouse. Fixture import re-inserts tree nodes with fresh lft/rgt, which
strands locations users add beneath them, so after_migrate rebuilds the
Location tree.

Asset Category fixture: Land (non-depreciable), Buildings (20 years),
Plant and Machinery, Vehicles, Furniture and Fixtures, Office Equipment,
Computers and Electronics, Software (5 years) and Intangible Assets
(10 years), per Royal Decree 145 rates; monthly straight-line, daily
pro-rata. The accounts table is company-specific and therefore not
shipped: an Asset Category before_import hook links every Thai company
(same contract as the WHT categories), reusing the Standard chart's
fixed asset accounts and creating Land, Vehicles and Intangible Assets
under Fixed Assets. Company.on_update links new companies. Depreciation
accounts are left to the Company defaults.

get_or_create_account now takes account_type and parent_groups.

default_thai_company/hooks.py

@@ -105,6 +105,30 @@ fixtures = [
 		],
 	},
 	{"doctype": "Tax Withholding Category", "filters": [["name", "like", "WHT %"]]},
+	{
+		"doctype": "Location",
+		"filters": [["name", "in", ["All Locations", "Head Office", "Branch Office", "Warehouse"]]],
+	},
+	{
+		"doctype": "Asset Category",
+		"filters": [
+			[
+				"name",
+				"in",
+				[
+					"Land",
+					"Buildings",
+					"Plant and Machinery",
+					"Vehicles",
+					"Furniture and Fixtures",
+					"Office Equipment",
+					"Computers and Electronics",
+					"Software",
+					"Intangible Assets",
+				],
+			]
+		],
+	},
 	# HRMS doctypes; skipped by sync_fixtures on sites without hrms
 	{"doctype": "Employee Tax Exemption Category"},
 	{"doctype": "Employee Tax Exemption Sub Category"},
@@ -117,6 +141,8 @@ fixtures = [
 # before_install = "default_thai_company.install.before_install"
 # Fixtures are synced before this runs; VAT schemes for companies that already exist.
 after_install = "default_thai_company.vat.setup_companies"
+# Fixture import re-inserts the Location tree; restore lft/rgt for user-added nodes.
+after_migrate = "default_thai_company.assets.rebuild_locations"
 
 # Uninstallation
 # ------------
@@ -179,10 +205,14 @@ doc_events = {
 	"Tax Withholding Category": {
 		"before_import": "default_thai_company.tax_withholding.prepare_fixture_accounts",
 	},
+	"Asset Category": {
+		"before_import": "default_thai_company.assets.prepare_fixture_accounts",
+	},
 	"Company": {
 		"on_update": [
 			"default_thai_company.tax_withholding.setup_company",
 			"default_thai_company.vat.setup_company",
+			"default_thai_company.assets.setup_company",
 		],
 	},
 	"Payment Entry": {