feat: initial terraform provider for artifactapi v0.0.1

Resources:
- artifactapi_remote: CRUD for remote proxy repositories
- artifactapi_virtual: CRUD for virtual (merged) repositories

Data sources:
- data.artifactapi_remote: read remote config
- data.artifactapi_virtual: read virtual config

Supports all 10 package types (generic, docker, helm, pypi, npm,
rpm, alpine, puppet, terraform, goproxy), allowlist/blocklist,
tag banning, quarantine, and terraform import.

internal/provider/provider.go

@@ -0,0 +1,70 @@
+package provider
+
+import (
+	"context"
+
+	"github.com/hashicorp/terraform-plugin-framework/datasource"
+	"github.com/hashicorp/terraform-plugin-framework/provider"
+	"github.com/hashicorp/terraform-plugin-framework/provider/schema"
+	"github.com/hashicorp/terraform-plugin-framework/resource"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+)
+
+var _ provider.Provider = &ArtifactAPIProvider{}
+
+type ArtifactAPIProvider struct {
+	version string
+}
+
+type artifactAPIProviderModel struct {
+	Endpoint types.String `tfsdk:"endpoint"`
+}
+
+func New(version string) func() provider.Provider {
+	return func() provider.Provider {
+		return &ArtifactAPIProvider{version: version}
+	}
+}
+
+func (p *ArtifactAPIProvider) Metadata(_ context.Context, _ provider.MetadataRequest, resp *provider.MetadataResponse) {
+	resp.TypeName = "artifactapi"
+	resp.Version = p.version
+}
+
+func (p *ArtifactAPIProvider) Schema(_ context.Context, _ provider.SchemaRequest, resp *provider.SchemaResponse) {
+	resp.Schema = schema.Schema{
+		Description: "Manage ArtifactAPI remotes and virtual repositories.",
+		Attributes: map[string]schema.Attribute{
+			"endpoint": schema.StringAttribute{
+				Description: "The ArtifactAPI server endpoint URL (e.g. https://artifactapi.example.com).",
+				Required:    true,
+			},
+		},
+	}
+}
+
+func (p *ArtifactAPIProvider) Configure(ctx context.Context, req provider.ConfigureRequest, resp *provider.ConfigureResponse) {
+	var config artifactAPIProviderModel
+	resp.Diagnostics.Append(req.Config.Get(ctx, &config)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	client := newAPIClient(config.Endpoint.ValueString())
+	resp.DataSourceData = client
+	resp.ResourceData = client
+}
+
+func (p *ArtifactAPIProvider) Resources(_ context.Context) []func() resource.Resource {
+	return []func() resource.Resource{
+		NewRemoteResource,
+		NewVirtualResource,
+	}
+}
+
+func (p *ArtifactAPIProvider) DataSources(_ context.Context) []func() datasource.DataSource {
+	return []func() datasource.DataSource{
+		NewRemoteDataSource,
+		NewVirtualDataSource,
+	}
+}