feat: add Calendar blueprint illustration

Transcribe the calendar blueprint from blueprint-ontology (README +
calendar.als): Navigate, Render, Load, Scope functions, its own
Idle/Loading/Refreshing/Error lifecycle, and a bespoke month/week
specimen. Composition follows the formal model (Async + Pullable).

src/data/blueprints.ts

@@ -6,8 +6,10 @@ import type { Component } from "vue"
 import type { Blueprint } from "./blueprint"
 import { list } from "./listBlueprint"
 import { grid } from "./gridBlueprint"
+import { calendar } from "./calendarBlueprint"
 import ListSpecimen from "@/specimens/ListSpecimen.vue"
 import GridSpecimen from "@/specimens/GridSpecimen.vue"
+import CalendarSpecimen from "@/specimens/CalendarSpecimen.vue"
 
 export interface RegistryEntry {
   blueprint: Blueprint
@@ -17,6 +19,7 @@ export interface RegistryEntry {
 export const REGISTRY: Record<string, RegistryEntry> = {
   list: { blueprint: list, specimen: ListSpecimen },
   grid: { blueprint: grid, specimen: GridSpecimen },
+  calendar: { blueprint: calendar, specimen: CalendarSpecimen },
 }
 
 export const BLUEPRINTS: Blueprint[] = Object.values(REGISTRY).map((e) => e.blueprint)