feat(infra): distribute terraform modules under infra/terraform

POC: lift the homelab-grown nextcloud-mcp-server and
nextcloud-mcp-deployer-role Terraform modules into this repo so external
operators can consume them via a `git::` source.

Includes a top-level README documenting the two-phase deploy flow
(bootstrap deployer role with a copy-pasteable IAM policy, then assume the
role to deploy the MCP server) and supports both in-VPC Qdrant and
external/managed Qdrant modes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

infra/terraform/nextcloud-mcp-server/main.tf

@@ -0,0 +1,15 @@
+terraform {
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 6.0"
+    }
+    random = {
+      source  = "hashicorp/random"
+      version = "~> 3.6"
+    }
+  }
+}
+
+data "aws_region" "current" {}
+data "aws_caller_identity" "current" {}