feat: start a project from another one's configuration

Creating a project can name one the creator owns or administers: its
statuses, transitions, types, areas, custom fields and automation rules
are copied once (paused rules stay paused; rules assigning to someone who
is not in the new project are left out). GraphQL templateProjectId, REST
template (id or key), MCP create_project template, and a select in the
web's new-project form.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/api/openapi.json

@@ -10656,6 +10656,12 @@
             "type": "boolean",
             "default": false,
             "description": "Anyone can read it without signing in (board, tickets, comments, releases, activity, statistics)"
+          },
+          "template": {
+            "type": "string",
+            "nullable": true,
+            "example": "API",
+            "description": "A project you own or administer (id or key) to start from: its statuses, transitions, types, areas, custom fields and automation rules are copied"
           }
         },
         "required": [