fix: remove matrix strategy from CI, use only mise

- Remove erlef/setup-beam compatibility testing
- Use single test job with mise for Elixir 1.18.4-otp-28
- Remove all conditional matrix logic
- Simplify caching strategy

This eliminates erlef/setup-beam version errors.

Author: vitalis

.github/workflows/ci.yml

@@ -10,116 +10,56 @@ env:
   MIX_ENV: test
 
 jobs:
-  # Matrix testing for compatibility (inspired by Anthropix)
+  # Single test job using mise
   test:
-    name: Test (Elixir ${{matrix.elixir}} / OTP ${{matrix.otp}})
+    name: Test and Lint
     runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          # Primary development version (uses mise)
-          - elixir: "mise"
-            otp: "mise"
-            use_mise: true
-            lint: true
-            coverage: true
-          # Compatibility testing (uses erlef/setup-beam)
-          - elixir: "1.17"
-            otp: "26"
-            use_mise: false
-          - elixir: "1.18"
-            otp: "27"
-            use_mise: false
-
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      # Setup using mise (for primary development version)
       - name: Install mise and tools
-        if: matrix.use_mise
         uses: jdx/mise-action@v3
         with:
           install: true
           cache: true
           github_token: ${{ secrets.GITHUB_TOKEN }}
 
-      # Setup using erlef/setup-beam (for compatibility testing)
-      - name: Setup Elixir
-        if: "!matrix.use_mise"
-        uses: erlef/setup-beam@v1
-        with:
-          elixir-version: ${{ matrix.elixir }}
-          otp-version: ${{ matrix.otp }}
-          version-type: strict
-
-      # Enhanced caching strategy
-      - name: Cache dependencies (mise)
-        if: matrix.use_mise
-        uses: actions/cache@v4
-        with:
-          path: |
-            deps/
-            _build/
-          key: ${{ runner.os }}-mise-mix-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}-${{ hashFiles('mise.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-mise-mix-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}-
-            ${{ runner.os }}-mise-mix-
-
-      - name: Cache dependencies (standard)
-        if: "!matrix.use_mise"
+      - name: Cache dependencies
         uses: actions/cache@v4
         with:
           path: |
             deps/
             _build/
-          key: ${{ runner.os }}-${{ matrix.elixir }}-otp${{ matrix.otp }}-mix-${{ hashFiles(format('{0}{1}', github.workspace, '/mix.lock')) }}
+          key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}-${{ hashFiles('mise.toml') }}
           restore-keys: |
-            ${{ runner.os }}-${{ matrix.elixir }}-otp${{ matrix.otp }}-mix-
+            ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}-
             ${{ runner.os }}-mix-
 
       - name: Install dependencies
         run: mix deps.get
 
-      # Conditional linting (inspired by OpenAI_ex)
       - name: Check code formatting
-        if: matrix.lint
         run: mix format --check-formatted
 
       - name: Check for unused dependencies
-        if: matrix.lint
         run: mix deps.unlock --check-unused
 
       - name: Run Credo
-        if: matrix.lint
         run: mix credo --strict
 
-      - name: Compile application (warnings as errors for lint job)
-        if: matrix.lint
+      - name: Compile application
         run: mix compile --warnings-as-errors
 
-      - name: Compile application (standard)
-        if: "!matrix.lint"
-        run: mix compile
-
-      - name: Run tests (with warnings as errors for lint job)
-        if: matrix.lint
+      - name: Run tests
         run: mix test --warnings-as-errors
 
-      - name: Run tests (standard)
-        if: "!matrix.lint"
-        run: mix test
-
-      # Coverage only on primary version
       - name: Generate coverage report
-        if: matrix.coverage
         run: mix coveralls.github
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Upload coverage artifacts
-        if: matrix.coverage
         uses: actions/upload-artifact@v4
         with:
           name: coverage-report