diff --git a/github/client.go b/github/client.go
index ab07a24..bd6f7e1 100644
--- a/github/client.go
+++ b/github/client.go
@@ -93,11 +93,16 @@ func (c *Client) SetHTTPClient(hc *http.Client) {
 }
 
 // doRequest performs an HTTP request with retry on 429 rate limit responses.
-// It respects the Retry-After header when present.
+// It respects the Retry-After header when present (capped at maxRetryAfter).
 func (c *Client) doRequest(ctx context.Context, method, url string, accept string) ([]byte, error) {
 	const maxAttempts = 3
-	backoff := c.RetryBackoff
-	if backoff == nil {
+	const maxRetryAfter = 120 * time.Second
+
+	var backoff []time.Duration
+	if c.RetryBackoff != nil {
+		backoff = make([]time.Duration, len(c.RetryBackoff))
+		copy(backoff, c.RetryBackoff)
+	} else {
 		backoff = []time.Duration{1 * time.Second, 2 * time.Second}
 	}
 
@@ -125,7 +130,9 @@ func (c *Client) doRequest(ctx context.Context, method, url string, accept strin
 		if err != nil {
 			return nil, fmt.Errorf("create request: %w", err)
 		}
-		req.Header.Set("Authorization", "Bearer "+c.token)
+		if c.token != "" {
+			req.Header.Set("Authorization", "Bearer "+c.token)
+		}
 		if accept != "" {
 			req.Header.Set("Accept", accept)
 		} else {
@@ -156,8 +163,12 @@ func (c *Client) doRequest(ctx context.Context, method, url string, accept strin
 			// Check for Retry-After header and override backoff if present
 			if ra := resp.Header.Get("Retry-After"); ra != "" {
 				if seconds, err := strconv.Atoi(ra); err == nil && seconds > 0 {
+					delay := time.Duration(seconds) * time.Second
+					if delay > maxRetryAfter {
+						delay = maxRetryAfter
+					}
 					if attempt < len(backoff) {
-						backoff[attempt] = time.Duration(seconds) * time.Second
+						backoff[attempt] = delay
 					}
 				}
 			}
diff --git a/github/client_test.go b/github/client_test.go
index e3cd121..e00e534 100644
--- a/github/client_test.go
+++ b/github/client_test.go
@@ -185,6 +185,9 @@ func TestIsUnauthorized(t *testing.T) {
 }
 
 func TestDoRequest_429RetryAfterHeader(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping slow retry test in short mode")
+	}
 	attempts := 0
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		attempts++
@@ -222,3 +225,39 @@ func TestDoRequest_429RetryAfterHeader(t *testing.T) {
 		t.Errorf("expected ~1s delay from Retry-After, got %v", elapsed)
 	}
 }
+
+func TestDoRequest_RetryAfterDoesNotMutateBackoff(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping slow retry test in short mode")
+	}
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			w.Header().Set("Retry-After", "1")
+			w.WriteHeader(429)
+			w.Write([]byte(`{"message":"rate limit"}`))
+			return
+		}
+		w.WriteHeader(200)
+		w.Write([]byte(`{"ok":true}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL)
+	c.SetHTTPClient(srv.Client())
+	c.RetryBackoff = []time.Duration{1 * time.Millisecond, 1 * time.Millisecond}
+
+	_, err := c.doGet(context.Background(), srv.URL+"/test")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	// Verify the original RetryBackoff slice was not mutated
+	if c.RetryBackoff[0] != 1*time.Millisecond {
+		t.Errorf("RetryBackoff[0] was mutated: got %v, want 1ms", c.RetryBackoff[0])
+	}
+	if c.RetryBackoff[1] != 1*time.Millisecond {
+		t.Errorf("RetryBackoff[1] was mutated: got %v, want 1ms", c.RetryBackoff[1])
+	}
+}
diff --git a/github/files.go b/github/files.go
index 9c162bf..a385623 100644
--- a/github/files.go
+++ b/github/files.go
@@ -11,8 +11,8 @@ import (
 	"gitea.weiker.me/rodin/review-bot/vcs"
 )
 
-// GetFileContent fetches a file from the default branch of a repo.
-// Delegates to GetFileContentAtRef with an empty ref.
+// GetFileContent fetches a file from a repo at the given ref.
+// Delegates to GetFileContentAtRef with the provided ref.
 func (c *Client) GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error) {
 	return c.GetFileContentAtRef(ctx, owner, repo, path, ref)
 }
@@ -47,12 +47,17 @@ func (c *Client) ListContents(ctx context.Context, owner, repo, path string) ([]
 
 // escapePath escapes each segment of a relative file path for use in URLs.
 // Slashes are preserved as path separators; other special characters are escaped.
+// Dot-segments ("." and "..") are removed to prevent path traversal.
 func escapePath(p string) string {
 	parts := strings.Split(p, "/")
-	for i, part := range parts {
-		parts[i] = url.PathEscape(part)
+	var clean []string
+	for _, part := range parts {
+		if part == "." || part == ".." || part == "" {
+			continue
+		}
+		clean = append(clean, url.PathEscape(part))
 	}
-	return strings.Join(parts, "/")
+	return strings.Join(clean, "/")
 }
 
 // decodeBase64Content decodes base64-encoded content from the GitHub contents API.
diff --git a/github/files_test.go b/github/files_test.go
index bb76a0b..0c077d6 100644
--- a/github/files_test.go
+++ b/github/files_test.go
@@ -275,3 +275,23 @@ func TestDecodeBase64Content_Invalid(t *testing.T) {
 		t.Fatal("expected error for invalid base64")
 	}
 }
+
+func TestEscapePath_RejectsDotSegments(t *testing.T) {
+	tests := []struct {
+		input string
+		want  string
+	}{
+		{"src/main.go", "src/main.go"},
+		{"../etc/passwd", "etc/passwd"},
+		{"./src/../main.go", "src/main.go"},
+		{"a/b/c", "a/b/c"},
+		{"file with spaces.go", "file%20with%20spaces.go"},
+		{"a/./b/../c", "a/b/c"},
+	}
+	for _, tt := range tests {
+		got := escapePath(tt.input)
+		if got != tt.want {
+			t.Errorf("escapePath(%q) = %q, want %q", tt.input, got, tt.want)
+		}
+	}
+}
diff --git a/github/pr.go b/github/pr.go
index 81bec09..0d1046f 100644
--- a/github/pr.go
+++ b/github/pr.go
@@ -205,7 +205,7 @@ func (c *Client) GetCommitStatuses(ctx context.Context, owner, repo, sha string)
 }
 
 // mapCheckRunStatus maps a check run conclusion+status to a vcs.CommitStatus status string.
-func mapCheckRunStatus(conclusion *string, status string) string {
+func mapCheckRunStatus(conclusion *string, _ string) string {
 	if conclusion == nil {
 		// Still running or queued
 		return "pending"
@@ -217,8 +217,6 @@ func mapCheckRunStatus(conclusion *string, status string) string {
 		return "failure"
 	case "cancelled", "skipped", "neutral":
 		return "success" // non-blocking
-	case "in_progress", "queued":
-		return "pending"
 	default:
 		return "pending"
 	}