feat: deepen skill test coverage — 52 → 247 cases across all 43 skills

Add 195 new test cases covering examples from SKILL.md, edge cases,
and parameter combinations. Create _skill.json for form-edit, skd-edit,
subsystem-edit. Add fixtures for negative validate cases. Fix
normalizeUuids in meta-validate/meta-info configs.

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

tests/skills/cases/mxl-validate/fixtures/bad-format-index/Template.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document xmlns="http://v8.1c.ru/8.2/data/spreadsheet" xmlns:style="http://v8.1c.ru/8.1/data/ui/style" xmlns:v8="http://v8.1c.ru/8.1/data/core" xmlns:v8ui="http://v8.1c.ru/8.1/data/ui" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<languageSettings>
+		<currentLanguage>ru</currentLanguage>
+		<defaultLanguage>ru</defaultLanguage>
+		<languageInfo>
+			<id>ru</id>
+			<code>Русский</code>
+			<description>Русский</description>
+		</languageInfo>
+	</languageSettings>
+	<columns>
+		<size>2</size>
+	</columns>
+	<rowsItem>
+		<index>0</index>
+		<row>
+			<c>
+				<i>0</i>
+				<c>
+					<f>99</f>
+					<tl>
+						<v8:item>
+							<v8:lang>ru</v8:lang>
+							<v8:content>Тест</v8:content>
+						</v8:item>
+					</tl>
+				</c>
+			</c>
+		</row>
+	</rowsItem>
+	<templateMode>true</templateMode>
+	<defaultFormatIndex>0</defaultFormatIndex>
+	<height>1</height>
+	<vgRows>1</vgRows>
+	<font faceName="Arial" height="10" bold="false" italic="false" underline="false" strikeout="false" kind="Absolute" scale="100"/>
+	<format>
+		<width>10</width>
+	</format>
+</document>