feat(api): create unified API server with first 3 modules

New consolidated Hono/Bun API server at apps/api/ that replaces individual
app servers. One process, one port, one auth middleware, one container.

Modules ported:
- calendar: RRULE expansion, ICS import, Google Calendar (stub)
- contacts: avatar upload (S3), vCard import/parsing
- mukke: audio upload/download presigned URLs, batch cover art

Architecture: each module registers routes under /api/v1/{module}/*
using the shared-hono middleware stack (auth, rate limit, error handler).

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

apps/api/package.json

@@ -0,0 +1,22 @@
+{
+	"name": "@manacore/api",
+	"version": "1.0.0",
+	"private": true,
+	"type": "module",
+	"scripts": {
+		"dev": "bun --hot run src/index.ts",
+		"build": "bun build src/index.ts --outdir dist --target bun",
+		"start": "bun run dist/index.js",
+		"type-check": "tsc --noEmit"
+	},
+	"dependencies": {
+		"@manacore/shared-hono": "workspace:*",
+		"@manacore/shared-storage": "workspace:*",
+		"hono": "^4.7.0",
+		"zod": "^3.23.0"
+	},
+	"devDependencies": {
+		"@types/bun": "latest",
+		"typescript": "^5.8.0"
+	}
+}