Add unit tests, integration test, CI workflow, and conventions

- gitea/client_test.go: mock HTTP tests for all API methods + error cases
- llm/client_test.go: mock tests for completion, errors, timeouts
- review/parser_test.go: JSON parsing, markdown fences, validation
- review/formatter_test.go: markdown output, empty/multiple findings
- review/prompt_test.go: system/user prompt construction
- integration_test.go: full end-to-end flow (build tag: integration)
- .gitea/workflows/ci.yml: test + vet + build on push, dual LLM review on PRs
- CONVENTIONS.md: coding standards for self-review dogfooding
- README.md: usage docs, env vars, architecture

.gitea/workflows/ci.yml

@@ -0,0 +1,53 @@
+name: CI
+on:
+  push:
+    branches: [main]
+  pull_request:
+    types: [opened, synchronize]
+
+jobs:
+  test:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.26"
+      - run: go test ./...
+      - run: go vet ./...
+      - run: go build -o review-bot ./cmd/review-bot
+
+  review:
+    runs-on: ubuntu-24.04
+    if: github.event_name == 'pull_request'
+    needs: test
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.26"
+      - run: go build -o review-bot ./cmd/review-bot
+      - name: Run Sonnet Review
+        env:
+          GITEA_URL: ${{ github.server_url }}
+          GITEA_REPO: ${{ github.repository }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+          REVIEWER_TOKEN: ${{ secrets.SONNET_REVIEW_TOKEN }}
+          LLM_BASE_URL: ${{ secrets.LLM_BASE_URL }}
+          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:
+          GITEA_URL: ${{ github.server_url }}
+          GITEA_REPO: ${{ github.repository }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+          REVIEWER_TOKEN: ${{ secrets.GPT_REVIEW_TOKEN }}
+          LLM_BASE_URL: ${{ secrets.LLM_BASE_URL }}
+          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