ci: add Go modules/build cache, fix master branch triggers

- Add actions/cache@v4 for GOMODCACHE and GOCACHE on lint/test/build
- Switch from setup-go built-in cache to explicit cache control
- Fix branch refs: main → master for PR, artifact, and docker jobs
- Use registry-based Docker layer caching (mode=max)
- Extract GO_VERSION env var for single-point version management

.gitea/workflows/ci.yml

@@ -4,7 +4,10 @@ on:
   push:
     branches: ["**"]
   pull_request:
-    branches: ["main"]
+    branches: ["master"]
+
+env:
+  GO_VERSION: "1.25"
 
 jobs:
   lint:
@@ -14,7 +17,17 @@ jobs:
 
       - uses: actions/setup-go@v5
         with:
-          go-version: "1.25"
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Cache Go modules
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/go/pkg/mod
+            ~/.cache/go-build
+          key: go-lint-${{ runner.os }}-${{ hashFiles('go.sum') }}
+          restore-keys: |
+            go-lint-${{ runner.os }}-
 
       - name: Download Go modules
         run: go mod download
@@ -39,7 +52,17 @@ jobs:
 
       - uses: actions/setup-go@v5
         with:
-          go-version: "1.25"
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Cache Go modules and build cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/go/pkg/mod
+            ~/.cache/go-build
+          key: go-test-${{ runner.os }}-${{ hashFiles('go.sum') }}
+          restore-keys: |
+            go-test-${{ runner.os }}-
 
       - name: Download Go modules
         run: go mod download
@@ -55,14 +78,26 @@ jobs:
 
       - uses: actions/setup-go@v5
         with:
-          go-version: "1.25"
-          cache: true
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Cache Go modules and build cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/go/pkg/mod
+            ~/.cache/go-build
+          key: go-build-${{ runner.os }}-${{ hashFiles('go.sum') }}
+          restore-keys: |
+            go-build-${{ runner.os }}-
+
+      - name: Download Go modules
+        run: go mod download
 
       - name: Build binary
         run: go build -o mrixscraft-server ./cmd/server
 
       - name: Upload artifact
-        if: github.ref == 'refs/heads/main'
+        if: github.ref == 'refs/heads/master'
         uses: actions/upload-artifact@v4
         with:
           name: mrixscraft-server
@@ -71,7 +106,7 @@ jobs:
   docker:
     runs-on: ubuntu-latest
     needs: build
-    if: github.ref == 'refs/heads/main'
+    if: github.ref == 'refs/heads/master'
     steps:
       - uses: actions/checkout@v4
 
@@ -93,5 +128,5 @@ jobs:
           tags: |
             gitea.mrixs.me/Mrixs/MrixsCraft-server:latest
             gitea.mrixs.me/Mrixs/MrixsCraft-server:${{ github.sha }}
-          cache-from: type=registry,ref=gitea.mrixs.me/Mrixs/MrixsCraft-server:latest
-          cache-to: type=inline
+          cache-from: type=registry,ref=gitea.mrixs.me/Mrixs/MrixsCraft-server:buildcache
+          cache-to: type=registry,ref=gitea.mrixs.me/Mrixs/MrixsCraft-server:buildcache,mode=max