ci: add release workflow + install script

- Release workflow: builds linux/darwin amd64/arm64 on tag push
- Injects version via -ldflags
- Creates Gitea release with binary assets + checksums
- install.sh: curl-pipe-bash installer from latest release
- Version variable in main.go for -version flag support

.gitea/workflows/ci.yml

@@ -1,4 +1,5 @@
 name: CI
+
 on:
   push:
     branches: [main]
@@ -12,7 +13,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
-          go-version: "1.26"
+          go-version: '1.26'
       - run: go test ./...
       - run: go vet ./...
       - run: go build -o review-bot ./cmd/review-bot
@@ -25,7 +26,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
-          go-version: "1.26"
+          go-version: '1.26'
       - run: go build -o review-bot ./cmd/review-bot
       - name: Run Sonnet Review
         env:
@@ -37,7 +38,6 @@ jobs:
           LLM_API_KEY: ${{ secrets.LLM_API_KEY }}
           LLM_MODEL: "anthropic--claude-4.6-sonnet"
           CONVENTIONS_FILE: "CONVENTIONS.md"
-          REVIEWER_NAME: "Sonnet"
         run: ./review-bot
       - name: Run GPT Review
         env:
@@ -49,5 +49,4 @@ jobs:
           LLM_API_KEY: ${{ secrets.LLM_API_KEY }}
           LLM_MODEL: "sap-ai-opus-latest-openai/gpt-5"
           CONVENTIONS_FILE: "CONVENTIONS.md"
-          REVIEWER_NAME: "GPT"
         run: ./review-bot