fix(installer): restore name field and use double quotes for Antigravity templates

The 'name' field is supported in Antigravity workflows. The previous loading issues were caused by single quotes wrapping the YAML frontmatter values, not the presence of the field itself. This update synchronizes Antigravity templates with default ones while ensuring double quotes are used for 'name' and 'description' fields.

tools/cli/installers/lib/ide/templates/combined/antigravity-agent.md

@@ -1,4 +1,5 @@
 ---
+name: "{{name}}"
 description: "{{description}}"
 ---
 

tools/cli/installers/lib/ide/templates/combined/antigravity-task.md

@@ -1,4 +1,5 @@
 ---
+name: "{{name}}"
 description: "{{description}}"
 ---
 

tools/cli/installers/lib/ide/templates/combined/antigravity-tool.md

@@ -1,4 +1,5 @@
 ---
+name: "{{name}}"
 description: "{{description}}"
 ---
 

tools/cli/installers/lib/ide/templates/combined/antigravity-workflow-yaml.md

@@ -1,4 +1,5 @@
 ---
+name: "{{name}}"
 description: "{{description}}"
 ---
 

tools/cli/installers/lib/ide/templates/combined/antigravity-workflow.md

@@ -1,4 +1,5 @@
 ---
+name: "{{name}}"
 description: "{{description}}"
 ---