feat: make api/v1 independently importable as a Go sub-module (#571)

Extract api/v1 into a standalone Go module (api/go.mod) so external
projects can `go get github.com/NexusGPU/tensor-fusion/api` without
pulling the entire operator dependency tree (NVML, AWS SDK, gorm, etc.).

- Add api/v1/constants.go with phase, condition, and domain constants
- Remove pkg/constants dependency from all api/v1 type files
- Add api/go.mod with minimal k8s v0.35.0 dependencies
- Add replace directive in root go.mod for local development
- Add release-api.yml workflow for automatic api module tagging

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: Code2Life

.github/workflows/release-api.yml

@@ -0,0 +1,93 @@
+name: Release API Module
+
+on:
+  push:
+    branches:
+      - main
+      - v1
+      - release/**
+    paths:
+      - "api/**"
+  workflow_dispatch:
+
+jobs:
+  release-api:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+          fetch-tags: true
+
+      - name: Check for api/ changes
+        id: changes
+        env:
+          EVENT_NAME: ${{ github.event_name }}
+        run: |
+          if [ "$EVENT_NAME" = "workflow_dispatch" ]; then
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+          # Compare with parent commit to see if api/ files changed
+          if git diff --name-only HEAD~1 HEAD | grep -q '^api/'; then
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Compute next api version
+        if: steps.changes.outputs.changed == 'true'
+        id: version
+        run: |
+          # Find latest api/v* tag
+          LATEST=$(git tag -l 'api/v*' --sort=-v:refname | head -1)
+          if [ -z "$LATEST" ]; then
+            NEXT="api/v0.1.0"
+          else
+            # Strip api/v prefix, bump patch
+            VER="${LATEST#api/v}"
+            MAJOR=$(echo "$VER" | cut -d. -f1)
+            MINOR=$(echo "$VER" | cut -d. -f2)
+            PATCH=$(echo "$VER" | cut -d. -f3)
+            PATCH=$((PATCH + 1))
+            NEXT="api/v${MAJOR}.${MINOR}.${PATCH}"
+          fi
+          echo "tag=$NEXT" >> "$GITHUB_OUTPUT"
+          echo "Next API version: $NEXT"
+
+      - name: Create and push tag
+        if: steps.changes.outputs.changed == 'true'
+        env:
+          TAG: ${{ steps.version.outputs.tag }}
+        run: |
+          git tag "$TAG"
+          git push origin "$TAG"
+
+      - name: Create GitHub release
+        if: steps.changes.outputs.changed == 'true'
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          TAG: ${{ steps.version.outputs.tag }}
+          COMMIT_SHA: ${{ github.sha }}
+        run: |
+          VER="${TAG#api/}"
+          PREV=$(git tag -l 'api/v*' --sort=-v:refname | sed -n '2p')
+          CHANGELOG=""
+          if [ -n "$PREV" ]; then
+            CHANGES=$(git log "${PREV}..${TAG}" --pretty=format:"- %s" -- api/)
+            if [ -n "$CHANGES" ]; then
+              CHANGELOG="### Changes
+          ${CHANGES}"
+            fi
+          fi
+          gh release create "$TAG" \
+            --title "API Module ${VER}" \
+            --target "$COMMIT_SHA" \
+            --notes "### Usage
+          \`\`\`bash
+          go get github.com/NexusGPU/tensor-fusion/api@${VER}
+          \`\`\`
+
+          ${CHANGELOG}"

api/go.mod

@@ -0,0 +1,75 @@
+module github.com/NexusGPU/tensor-fusion/api
+
+go 1.25.5
+
+require (
+	k8s.io/api v0.35.0
+	k8s.io/apimachinery v0.35.0
+	k8s.io/kube-scheduler v0.35.0
+	sigs.k8s.io/controller-runtime v0.23.1
+)
+
+require (
+	cel.dev/expr v0.24.0 // indirect
+	github.com/antlr4-go/antlr/v4 v4.13.0 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/blang/semver/v4 v4.0.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/emicklei/go-restful/v3 v3.12.2 // indirect
+	github.com/fxamacker/cbor/v2 v2.9.0 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-openapi/jsonpointer v0.21.0 // indirect
+	github.com/go-openapi/jsonreference v0.20.2 // indirect
+	github.com/go-openapi/swag v0.23.0 // indirect
+	github.com/google/cel-go v0.26.0 // indirect
+	github.com/google/gnostic-models v0.7.0 // indirect
+	github.com/google/go-cmp v0.7.0 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/josharian/intern v1.0.0 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/mailru/easyjson v0.7.7 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.3-0.20250322232337-35a7c28c31ee // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_golang v1.23.2 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
+	github.com/prometheus/common v0.66.1 // indirect
+	github.com/prometheus/procfs v0.16.1 // indirect
+	github.com/spf13/cobra v1.10.0 // indirect
+	github.com/spf13/pflag v1.0.9 // indirect
+	github.com/stoewer/go-strcase v1.3.0 // indirect
+	github.com/x448/float16 v0.8.4 // indirect
+	go.opentelemetry.io/otel v1.36.0 // indirect
+	go.opentelemetry.io/otel/trace v1.36.0 // indirect
+	go.yaml.in/yaml/v2 v2.4.3 // indirect
+	go.yaml.in/yaml/v3 v3.0.4 // indirect
+	golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 // indirect
+	golang.org/x/net v0.47.0 // indirect
+	golang.org/x/oauth2 v0.30.0 // indirect
+	golang.org/x/sync v0.18.0 // indirect
+	golang.org/x/sys v0.38.0 // indirect
+	golang.org/x/term v0.37.0 // indirect
+	golang.org/x/text v0.31.0 // indirect
+	golang.org/x/time v0.9.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20250303144028-a0af3efb3deb // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250528174236-200df99c418a // indirect
+	google.golang.org/protobuf v1.36.8 // indirect
+	gopkg.in/evanphx/json-patch.v4 v4.13.0 // indirect
+	gopkg.in/inf.v0 v0.9.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+	k8s.io/apiserver v0.35.0 // indirect
+	k8s.io/client-go v0.35.0 // indirect
+	k8s.io/component-base v0.35.0 // indirect
+	k8s.io/component-helpers v0.35.0 // indirect
+	k8s.io/dynamic-resource-allocation v0.35.0 // indirect
+	k8s.io/klog/v2 v2.130.1 // indirect
+	k8s.io/kube-openapi v0.0.0-20250910181357-589584f1c912 // indirect
+	k8s.io/utils v0.0.0-20251002143259-bc988d571ff4 // indirect
+	sigs.k8s.io/json v0.0.0-20250730193827-2d320260d730 // indirect
+	sigs.k8s.io/randfill v1.0.0 // indirect
+	sigs.k8s.io/structured-merge-diff/v6 v6.3.2-0.20260122202528-d9cc6641c482 // indirect
+	sigs.k8s.io/yaml v1.6.0 // indirect
+)