Add commit URL to Slack notifications with link and backtick formatting

- Add commit_url column to webhook_events and deployments tables
- Extract commit URL from webhook payload (from commit object or repo URL)
- Format Slack messages with backticks for branch and commit SHA
- Link commit SHA to the actual commit URL on the git server
- Keep plain text format for ntfy notifications

internal/service/webhook/webhook.go

@@ -50,10 +50,12 @@ type GiteaPushPayload struct {
 	Ref        string `json:"ref"`
 	Before     string `json:"before"`
 	After      string `json:"after"`
+	CompareURL string `json:"compare_url"`
 	Repository struct {
 		FullName string `json:"full_name"`
 		CloneURL string `json:"clone_url"`
 		SSHURL   string `json:"ssh_url"`
+		HTMLURL  string `json:"html_url"`
 	} `json:"repository"`
 	Pusher struct {
 		Username string `json:"username"`
@@ -61,6 +63,7 @@ type GiteaPushPayload struct {
 	} `json:"pusher"`
 	Commits []struct {
 		ID      string `json:"id"`
+		URL     string `json:"url"`
 		Message string `json:"message"`
 		Author  struct {
 			Name  string `json:"name"`
@@ -90,6 +93,7 @@ func (svc *Service) HandleWebhook(
 	// Extract branch from ref
 	branch := extractBranch(pushPayload.Ref)
 	commitSHA := pushPayload.After
+	commitURL := extractCommitURL(pushPayload)
 
 	// Check if branch matches
 	matched := branch == app.Branch
@@ -100,6 +104,7 @@ func (svc *Service) HandleWebhook(
 	event.EventType = eventType
 	event.Branch = branch
 	event.CommitSHA = sql.NullString{String: commitSHA, Valid: commitSHA != ""}
+	event.CommitURL = sql.NullString{String: commitURL, Valid: commitURL != ""}
 	event.Payload = sql.NullString{String: string(payload), Valid: true}
 	event.Matched = matched
 	event.Processed = false
@@ -160,3 +165,21 @@ func extractBranch(ref string) string {
 
 	return ref
 }
+
+// extractCommitURL extracts the commit URL from the webhook payload.
+// Prefers the URL from the head commit, falls back to constructing from repo URL.
+func extractCommitURL(payload GiteaPushPayload) string {
+	// Try to find the URL from the head commit (matching After SHA)
+	for _, commit := range payload.Commits {
+		if commit.ID == payload.After && commit.URL != "" {
+			return commit.URL
+		}
+	}
+
+	// Fall back to constructing URL from repo HTML URL
+	if payload.Repository.HTMLURL != "" && payload.After != "" {
+		return payload.Repository.HTMLURL + "/commit/" + payload.After
+	}
+
+	return ""
+}