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

integration_test.go

@@ -0,0 +1,103 @@
+//go:build integration
+
+package main
+
+import (
+	"os"
+	"strconv"
+	"testing"
+
+	"gitea.weiker.me/rodin/review-bot/gitea"
+	"gitea.weiker.me/rodin/review-bot/llm"
+	"gitea.weiker.me/rodin/review-bot/review"
+)
+
+// Integration test requires a running Gitea instance and LLM endpoint.
+// Set environment variables:
+//   INTEGRATION_GITEA_URL     - Gitea base URL
+//   INTEGRATION_GITEA_TOKEN   - Gitea API token with repo access
+//   INTEGRATION_GITEA_REPO    - owner/repo with an open PR
+//   INTEGRATION_PR_NUMBER     - PR number to test against
+//   INTEGRATION_LLM_BASE_URL  - LLM API base URL
+//   INTEGRATION_LLM_API_KEY   - LLM API key
+//   INTEGRATION_LLM_MODEL     - Model name
+
+func TestIntegration_FullReviewFlow(t *testing.T) {
+	giteaURL := os.Getenv("INTEGRATION_GITEA_URL")
+	giteaToken := os.Getenv("INTEGRATION_GITEA_TOKEN")
+	giteaRepo := os.Getenv("INTEGRATION_GITEA_REPO")
+	prNumStr := os.Getenv("INTEGRATION_PR_NUMBER")
+	llmBaseURL := os.Getenv("INTEGRATION_LLM_BASE_URL")
+	llmAPIKey := os.Getenv("INTEGRATION_LLM_API_KEY")
+	llmModel := os.Getenv("INTEGRATION_LLM_MODEL")
+
+	if giteaURL == "" || giteaToken == "" || giteaRepo == "" || prNumStr == "" ||
+		llmBaseURL == "" || llmAPIKey == "" || llmModel == "" {
+		t.Skip("Integration test env vars not set, skipping")
+	}
+
+	prNumber, err := strconv.Atoi(prNumStr)
+	if err != nil {
+		t.Fatalf("Invalid PR number %q: %v", prNumStr, err)
+	}
+
+	// Parse owner/repo
+	owner, repoName := "", ""
+	for i, c := range giteaRepo {
+		if c == / {
+			owner = giteaRepo[:i]
+			repoName = giteaRepo[i+1:]
+			break
+		}
+	}
+	if owner == "" || repoName == "" {
+		t.Fatalf("Invalid repo format %q", giteaRepo)
+	}
+
+	// Step 1: Fetch PR
+	giteaClient := gitea.NewClient(giteaURL, giteaToken)
+	pr, err := giteaClient.GetPullRequest(owner, repoName, prNumber)
+	if err != nil {
+		t.Fatalf("GetPullRequest: %v", err)
+	}
+	t.Logf("PR: %s (sha: %s)", pr.Title, pr.Head.Sha)
+
+	// Step 2: Fetch diff
+	diff, err := giteaClient.GetPullRequestDiff(owner, repoName, prNumber)
+	if err != nil {
+		t.Fatalf("GetPullRequestDiff: %v", err)
+	}
+	if diff == "" {
+		t.Fatal("diff is empty")
+	}
+	t.Logf("Diff size: %d bytes", len(diff))
+
+	// Step 3: Build prompts
+	systemPrompt := review.BuildSystemPrompt("")
+	userPrompt := review.BuildUserPrompt(pr.Title, pr.Body, diff, true, "")
+
+	// Step 4: Call LLM
+	llmClient := llm.NewClient(llmBaseURL, llmAPIKey, llmModel)
+	response, err := llmClient.Complete([]llm.Message{
+		{Role: "system", Content: systemPrompt},
+		{Role: "user", Content: userPrompt},
+	})
+	if err != nil {
+		t.Fatalf("LLM Complete: %v", err)
+	}
+	t.Logf("LLM response: %d bytes", len(response))
+
+	// Step 5: Parse response
+	result, err := review.ParseResponse(response)
+	if err != nil {
+		t.Fatalf("ParseResponse: %v", err)
+	}
+	t.Logf("Verdict: %s, Findings: %d", result.Verdict, len(result.Findings))
+
+	// Step 6: Format (dry-run validation)
+	body := review.FormatMarkdown(result, "integration-test")
+	if body == "" {
+		t.Fatal("formatted review body is empty")
+	}
+	t.Logf("Review body:\n%s", body)
+}