Add local_generic rootfs-images repository

Declares a local generic (raw-file) repo for bootapi's node rootfs tarballs and
wires the local_generic kind through the module. Depends on
terraform-provider-artifactapi #12 releasing v0.1.4 (adds artifactapi_local_generic);
the provider version pin is bumped to 0.1.4, so plan/validate stay red until that
release is available.

- config/local_generic/rootfs-images.yaml (new repo).
- local_generic wiring: config.hcl, module variables.tf + main.tf, env
  terragrunt.hcl inputs; provider pin 0.1.3 -> 0.1.4.

Claude-Session: https://claude.ai/code/session_015ur3i7D2azsMAWTSVABApv

modules/artifactapi/main.tf

@@ -117,6 +117,13 @@ resource "artifactapi_local_docker" "this" {
   description = each.value.description
 }
 
+resource "artifactapi_local_generic" "this" {
+  for_each = var.local_generic
+
+  name        = each.key
+  description = each.value.description
+}
+
 resource "artifactapi_virtual" "this" {
   for_each = var.virtual