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>

.gitea/workflows/version-check.yaml

@@ -0,0 +1,25 @@
+name: Version Check
+
+on:
+  pull_request:
+    paths:
+      - 'main.go'
+      - 'internal/**'
+
+jobs:
+  check-version:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Check version bump
+        run: |
+          BASE_VERSION=$(git show origin/${{ github.base_ref }}:main.go | grep -oP 'version string = "\K[^"]+')
+          HEAD_VERSION=$(grep -oP 'version string = "\K[^"]+' main.go)
+          if [ "$BASE_VERSION" = "$HEAD_VERSION" ]; then
+            echo "::warning::Version in main.go has not been bumped (still ${HEAD_VERSION}). Consider updating it for this release."
+          else
+            echo "Version bumped: ${BASE_VERSION} → ${HEAD_VERSION}"
+          fi