Overhaul VirtFusion provider: 20 resources, 30 data sources, multipage pagination

Complete rewrite of the VirtFusion Terraform provider with full API coverage:

- 20 managed resources (server, build, SSH key, user, firewall, IP blocks, etc.)
- 30 data sources (hypervisors, packages, servers, IP blocks, self-service, etc.)
- New HTTP client with proper error handling, query parameter support, and
  automatic multipage pagination via GetAllPages (fetches all pages from
  Laravel-style paginated endpoints and merges into a single response)
- Fixed type mismatches against live API: ServerData.Suspended (int→bool),
  IPBlockData.Type (string→int), PackageData json tags (primaryStorage, etc.),
  ServerData nested CPU/Settings/Resources structure, HypervisorGroupResources
  array response
- Configurable results-per-page (default 300) on all list data sources
- Migrated CI from GitHub Actions to Gitea Actions
- Updated goreleaser config, go.mod dependencies, and examples

Verified against live VirtFusion instance at cp.vps.ezscale.tech:
all data sources return correct data with full pagination support.

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

internal/provider/data_source_iso.go

@@ -0,0 +1,99 @@
+// Copyright (c) EZSCALE.
+// SPDX-License-Identifier: MPL-2.0
+
+package provider
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"terraform-provider-virtfusion/internal/client"
+
+	"github.com/hashicorp/terraform-plugin-framework/datasource"
+	"github.com/hashicorp/terraform-plugin-framework/datasource/schema"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+)
+
+var (
+	_ datasource.DataSource              = &ISODataSource{}
+	_ datasource.DataSourceWithConfigure = &ISODataSource{}
+)
+
+// NewISODataSource returns a new ISO data source.
+func NewISODataSource() datasource.DataSource {
+	return &ISODataSource{}
+}
+
+// ISODataSource defines the data source implementation.
+type ISODataSource struct {
+	client *client.Client
+}
+
+// ISODataSourceModel describes the data source data model.
+type ISODataSourceModel struct {
+	ID   types.Int64  `tfsdk:"id"`
+	Name types.String `tfsdk:"name"`
+}
+
+func (d *ISODataSource) Metadata(_ context.Context, req datasource.MetadataRequest, resp *datasource.MetadataResponse) {
+	resp.TypeName = req.ProviderTypeName + "_iso"
+}
+
+func (d *ISODataSource) Schema(_ context.Context, _ datasource.SchemaRequest, resp *datasource.SchemaResponse) {
+	resp.Schema = schema.Schema{
+		MarkdownDescription: "Fetches a single VirtFusion ISO by ID.",
+		Attributes: map[string]schema.Attribute{
+			"id": schema.Int64Attribute{
+				MarkdownDescription: "The ISO ID.",
+				Required:            true,
+			},
+			"name": schema.StringAttribute{
+				MarkdownDescription: "The ISO name.",
+				Computed:            true,
+			},
+		},
+	}
+}
+
+func (d *ISODataSource) Configure(_ context.Context, req datasource.ConfigureRequest, resp *datasource.ConfigureResponse) {
+	if req.ProviderData == nil {
+		return
+	}
+
+	c, ok := req.ProviderData.(*client.Client)
+	if !ok {
+		resp.Diagnostics.AddError(
+			"Unexpected Data Source Configure Type",
+			fmt.Sprintf("Expected *client.Client, got: %T.", req.ProviderData),
+		)
+		return
+	}
+
+	d.client = c
+}
+
+func (d *ISODataSource) Read(ctx context.Context, req datasource.ReadRequest, resp *datasource.ReadResponse) {
+	var data ISODataSourceModel
+	resp.Diagnostics.Append(req.Config.Get(ctx, &data)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	rawResp, err := d.client.Get(ctx, fmt.Sprintf("/media/iso/%d", data.ID.ValueInt64()))
+	if err != nil {
+		resp.Diagnostics.AddError("Error Reading ISO", err.Error())
+		return
+	}
+
+	var isoResp client.ISOResponse
+	if err := json.Unmarshal(rawResp, &isoResp); err != nil {
+		resp.Diagnostics.AddError("Error Parsing ISO Response", err.Error())
+		return
+	}
+
+	data.ID = types.Int64Value(isoResp.Data.ID)
+	data.Name = types.StringValue(isoResp.Data.Name)
+
+	resp.Diagnostics.Append(resp.State.Set(ctx, &data)...)
+}