Add persona system for specialized review roles. Each persona defines:
- A specific review focus (security, architecture, documentation)
- Custom system prompt additions
- Personality/tone adjustments

Built-in personas: security, architect, docs
Custom personas: load from JSON via persona-file flag

Includes workspace validation to prevent path traversal attacks.

Closes #51

@@ -94,0 +106,4 @@
+		var err error
+		persona, err = review.LoadBuiltinPersona(*personaName)
+		if err != nil {
+			slog.Error("failed to load persona", "persona", *personaName, "error", err)

@@ -71,6 +71,14 @@ inputs:
     required: false
     default: 'true'
   system-prompt-file:
+  persona:

@@ -94,0 +107,4 @@
+		persona, err = review.LoadBuiltinPersona(*personaName)
+		if err != nil {
+			slog.Error("failed to load persona", "persona", *personaName, "error", err)
+			os.Exit(1)

@@ -94,0 +102,4 @@
+
+	// Load persona if specified
+	var persona *review.Persona
+	if *personaName != "" {

@@ -0,0 +30,4 @@
+	Major string `json:"major"`
+	Minor string `json:"minor"`
+	Nit   string `json:"nit"`
+}

@@ -72,2 +72,4 @@
     default: 'true'
   system-prompt-file:
+  persona:
+    description: 'Built-in persona name (security, architect, docs)'

@@ -94,0 +111,4 @@
+		}
+		slog.Info("loaded built-in persona", "persona", persona.Name, "display", persona.DisplayName)
+	} else if *personaFile != "" {
+		var err error

@@ -56,0 +57,4 @@
+// FormatMarkdownWithDisplay formats a ReviewResult with separate display name and sentinel name.
+// displayName is used for the header title, sentinelName is used for the cleanup sentinel.
+// If displayName is empty, sentinelName is used for both.
+func FormatMarkdownWithDisplay(result *ReviewResult, displayName, sentinelName string) string {

@@ -94,0 +109,4 @@
+			os.Exit(1)
+		}
+		slog.Info("loaded built-in persona", "persona", persona.Name, "display", persona.DisplayName)
+	} else if *personaFile != "" {

@@ -0,0 +1,353 @@
+# Design: Role-based Review Personas (Issue #51)

@@ -56,0 +59,4 @@
+// If displayName is empty, sentinelName is used for both.
+func FormatMarkdownWithDisplay(result *ReviewResult, displayName, sentinelName string) string {
+	var sb strings.Builder
+

@@ -94,0 +97,4 @@
+	if *personaName != "" && *personaFile != "" {
+		slog.Error("--persona and --persona-file are mutually exclusive")
+		os.Exit(1)
+	}

@@ -0,0 +38,4 @@
+	if err != nil {
+		return nil, fmt.Errorf("read persona file %s: %w", path, err)
+	}
+	return parsePersona(data, path)

@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/exec"

@@ -0,0 +1,353 @@
+# Design: Role-based Review Personas (Issue #51)

@@ -56,0 +56,4 @@
+
+// FormatMarkdownWithDisplay formats a ReviewResult with separate display name and sentinel name.
+// displayName is used for the header title, sentinelName is used for the cleanup sentinel.
+// If displayName is empty, sentinelName is used for both.

@@ -56,0 +62,4 @@
+
+	// Use display name for header, or fall back to sentinel name
+	headerName := displayName
+	if headerName == "" {

@@ -0,0 +83,4 @@
+	sb.WriteString("- If the diff has no changes relevant to your focus areas, APPROVE with no findings.\n")
+
+	// Custom output format if provided
+	if p.OutputFormat != "" {

@@ -0,0 +188,4 @@
+	dir := t.TempDir()
+	path := filepath.Join(dir, "invalid.json")
+	if err := os.WriteFile(path, []byte("not json"), 0644); err != nil {
+		t.Fatalf("failed to write test file: %v", err)

@@ -293,7 +311,12 @@ func main() {
 	slog.Info("review parsed", "verdict", result.Verdict, "findings", len(result.Findings))

@@ -590,0 +627,4 @@
+	fullPath = filepath.Clean(fullPath)
+	// Check path is within workspace
+	if !strings.HasPrefix(fullPath, absWorkspace+string(filepath.Separator)) && fullPath != absWorkspace {
+		return "", fmt.Errorf("%s resolves outside workspace: path=%s workspace=%s", pathName, fullPath, absWorkspace)

@@ -48,0 +92,4 @@
+		{
+			name:      "valid nested path",
+			workspace: tmpDir,
+			path:      "subdir/nested.json",

@@ -56,0 +57,4 @@
+// FormatMarkdownWithDisplay formats a ReviewResult with separate display name and sentinel name.
+// displayName is used for the header title, sentinelName is used for the cleanup sentinel.
+// If displayName is empty, sentinelName is used for both.
+func FormatMarkdownWithDisplay(result *ReviewResult, displayName, sentinelName string) string {

@@ -71,6 +71,14 @@ inputs:
     required: false
     default: 'true'
   system-prompt-file:
+  persona:

@@ -91,6 +93,33 @@ func main() {
 		os.Exit(1)
 	}

@@ -0,0 +1,353 @@
+# Design: Role-based Review Personas (Issue #51)

@@ -53,3 +53,48 @@ func GiteaEvent(verdict string) string {
 		return "COMMENT"
 	}
 }
+

@@ -0,0 +4,4 @@
+	"embed"
+	"encoding/json"
+	"fmt"
+	"os"

@@ -0,0 +82,4 @@
+	sb.WriteString("- Line numbers should reference the new file line numbers from the diff headers.\n")
+	sb.WriteString("- If the diff has no changes relevant to your focus areas, APPROVE with no findings.\n")
+
+	// Custom output format if provided

@@ -0,0 +191,4 @@
+		t.Fatalf("failed to write test file: %v", err)
+	}
+
+	_, err := LoadPersona(path)

@@ -7,6 +7,7 @@ import (
 	"os"

@@ -0,0 +1,353 @@
+# Design: Role-based Review Personas (Issue #51)

@@ -53,3 +53,48 @@ func GiteaEvent(verdict string) string {
 		return "COMMENT"
 	}
 }
+

@@ -0,0 +82,4 @@
+	sb.WriteString("- Line numbers should reference the new file line numbers from the diff headers.\n")
+	sb.WriteString("- If the diff has no changes relevant to your focus areas, APPROVE with no findings.\n")
+
+	// Custom output format if provided

@@ -0,0 +194,4 @@
+	_, err := LoadPersona(path)
+	if err == nil {
+		t.Error("expected error for invalid JSON")
+	}

@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/exec"
 	"strings"

@@ -0,0 +1,353 @@
+# Design: Role-based Review Personas (Issue #51)

@@ -53,3 +53,48 @@ func GiteaEvent(verdict string) string {
 		return "COMMENT"
 	}
 }
+

@@ -0,0 +1,98 @@
+package review
+
+import (

@@ -0,0 +55,4 @@
+	sb.WriteString("CONTEXT:\n")
+	sb.WriteString("- You will receive the full content of modified files for reference, followed by the diff showing what changed.\n")
+	sb.WriteString("- The diff shows ONLY what was added/removed. The full file content provides complete context.\n")
+	sb.WriteString("- Focus your review on the CHANGES (the diff), using the full files for context.\n\n")

@@ -0,0 +193,4 @@
+
+	_, err := LoadPersona(path)
+	if err == nil {
+		t.Error("expected error for invalid JSON")

@@ -587,6 +610,36 @@ func validateReviewerName(name string) error {
 	return nil

@@ -56,0 +63,4 @@
+	// Use display name for header, or fall back to sentinel name
+	headerName := displayName
+	if headerName == "" {
+		headerName = sentinelName

@@ -45,6 +46,113 @@ func TestValidateReviewerName(t *testing.T) {
 	}

@@ -7,6 +7,7 @@ import (
 	"os"

@@ -0,0 +1,353 @@
+# Design: Role-based Review Personas (Issue #51)

@@ -53,3 +53,48 @@ func GiteaEvent(verdict string) string {
 		return "COMMENT"
 	}
 }
+

@@ -0,0 +2,4 @@
+
+import (
+	"embed"
+	"encoding/json"

@@ -0,0 +67,4 @@
+	sb.WriteString("  \"findings\": [\n")
+	sb.WriteString("    {\n")
+	sb.WriteString("      \"severity\": \"MAJOR\" or \"MINOR\" or \"NIT\",\n")
+	sb.WriteString("      \"file\": \"path/to/file\",\n")

@@ -0,0 +193,4 @@
+
+	_, err := LoadPersona(path)
+	if err == nil {
+		t.Error("expected error for invalid JSON")

@@ -0,0 +16,4 @@
+type Persona struct {
+	Name         string   `json:"name"`
+	DisplayName  string   `json:"display_name"`
+	ModelPref    string   `json:"model_preference,omitempty"`

@@ -0,0 +1,118 @@
+package review

@@ -590,0 +625,4 @@
+	// Join and clean the path
+	fullPath := filepath.Join(absWorkspace, path)
+	fullPath = filepath.Clean(fullPath)
+	// Check path is within workspace

@@ -332,0 +404,4 @@
+  - Decimal precision for money
+
+ignore:
+  - Code style

@@ -72,2 +72,4 @@
 	llmProvider := flag.String("llm-provider", envOrDefault("LLM_PROVIDER", "openai"), "LLM API provider: openai or anthropic")
+	personaName := flag.String("persona", envOrDefault("PERSONA", ""), "Built-in persona name (security, architect, docs)")
+	personaFile := flag.String("persona-file", envOrDefault("PERSONA_FILE", ""), "Path to persona JSON file")
 

@@ -48,2 +154,4 @@
+
+
 func makeReview(id int64, login, state string, stale bool, body string) gitea.Review {
 	r := gitea.Review{

@@ -2,2 +2,4 @@
 
 go 1.26.2
+
+require gopkg.in/yaml.v3 v3.0.1 // indirect

@@ -0,0 +9,4 @@
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)

@@ -0,0 +75,4 @@
+		}
+	}
+	return names
+}

@@ -0,0 +86,4 @@
+		if err := json.Unmarshal(data, &p); err != nil {
+			return nil, fmt.Errorf("parse persona %s: %w", source, err)
+		}
+	} else {

@@ -0,0 +93,4 @@
+		}
+	}
+	
+	if err := validatePersona(&p, source); err != nil {

@@ -0,0 +65,4 @@
+	sb.WriteString("  \"verdict\": \"APPROVE\" or \"REQUEST_CHANGES\",\n")
+	sb.WriteString("  \"summary\": \"Brief overall assessment (1-3 sentences)\",\n")
+	sb.WriteString("  \"findings\": [\n")
+	sb.WriteString("    {\n")

@@ -0,0 +91,4 @@
+	return sb.String()
+}
+
+// BuildSystemPromptWithPersona constructs the full system prompt, using either

@@ -77,2 +83,4 @@
+    required: false
+    default: ''
 
 runs:

@@ -587,6 +610,36 @@ func validateReviewerName(name string) error {
 	return nil

@@ -0,0 +297,4 @@
+
+## Design Review Findings (Self-Review)
+
+### Finding 1: Severity Mapping

@@ -2,2 +2,4 @@
 
 go 1.26.2
+
+require gopkg.in/yaml.v3 v3.0.1 // indirect

@@ -0,0 +14,4 @@
+//go:embed personas/*.yaml
+var embeddedPersonas embed.FS
+
+// Persona defines a specialized review role with focused expertise.

@@ -2,2 +2,4 @@
 
 go 1.26.2
+
+require gopkg.in/yaml.v3 v3.0.1 // indirect

@@ -56,0 +58,4 @@
+// displayName is used for the header title, sentinelName is used for the cleanup sentinel.
+// If displayName is empty, sentinelName is used for both.
+func FormatMarkdownWithDisplay(result *ReviewResult, displayName, sentinelName string) string {
+	var sb strings.Builder

@@ -0,0 +30,4 @@
+// These are prompt guidance for the LLM, not output format changes.
+type Severity struct {
+	Major string `json:"major" yaml:"major"`
+	Minor string `json:"minor" yaml:"minor"`

@@ -48,3 +155,4 @@
+
 func makeReview(id int64, login, state string, stale bool, body string) gitea.Review {
 	r := gitea.Review{
 		ID:    id,

@@ -2,2 +2,4 @@
 
 go 1.26.2
+
+require github.com/goccy/go-yaml v1.19.2

@@ -10,0 +24,4 @@
+
+// FormatMarkdownWithDisplay formats a ReviewResult with separate display name and sentinel name.
+// Note: displayName is not HTML-escaped as Gitea sanitizes rendered Markdown.
+// Persona display names are controlled by repo owners (trusted input).

@@ -0,0 +57,4 @@
+}
+
+// ListBuiltinPersonas returns the names of all built-in personas.
+func ListBuiltinPersonas() []string {

@@ -0,0 +79,4 @@
+
+func parsePersona(data []byte, source string) (*Persona, error) {
+	var p Persona
+	

@@ -0,0 +83,4 @@
+	// Determine format by extension or try YAML first (it's a superset of JSON)
+	ext := strings.ToLower(filepath.Ext(source))
+	if ext == ".json" {
+		if err := json.Unmarshal(data, &p); err != nil {

@@ -0,0 +223,4 @@
+
+func TestLoadPersonaFileNotFound(t *testing.T) {
+	_, err := LoadPersona("/nonexistent/path/persona.yaml")
+	if err == nil {

@@ -10,0 +18,4 @@
+	case "REQUEST_CHANGES":
+		return "REQUEST_CHANGES"
+	default:
+		return "COMMENT"

@@ -0,0 +97,4 @@
+		return nil, err
+	}
+	return &p, nil
+}

@@ -77,2 +83,4 @@
+    required: false
+    default: ''
 
 runs:

@@ -48,0 +77,4 @@
+	defer os.Setenv("GITHUB_WORKSPACE", origWorkspace)
+
+	tests := []struct {
+		name      string

@@ -0,0 +301,4 @@
+The persona YAML allows `critical` severity, but the LLM output parser (`review/parser.go`) only accepts MAJOR/MINOR/NIT. 
+
+**Resolution:** Keep standard output format. Persona severity section is ONLY for calibrating the LLM's judgment (prompt guidance). Output must still use MAJOR/MINOR/NIT. Document this clearly in persona format docs.
+

@@ -2,2 +2,4 @@
 
 go 1.26.2
+
+require github.com/goccy/go-yaml v1.19.2

@@ -10,0 +25,4 @@
+// FormatMarkdownWithDisplay formats a ReviewResult with separate display name and sentinel name.
+// Note: displayName is not HTML-escaped as Gitea sanitizes rendered Markdown.
+// Persona display names are controlled by repo owners (trusted input).
+// displayName is used for the header title, sentinelName is used for the cleanup sentinel.

@@ -0,0 +45,4 @@
+}
+
+// LoadBuiltinPersona loads a built-in persona by name.
+// Returns an error if the persona doesn't exist.

@@ -0,0 +1,330 @@
+# Design: Role-based Review Personas (Issue #51)

@@ -2,2 +2,4 @@
 
 go 1.26.2
+
+require github.com/goccy/go-yaml v1.19.2

@@ -14,0 +33,4 @@
+	// Use display name for header, or fall back to sentinel name
+	headerName := displayName
+	if headerName == "" {
+		headerName = sentinelName

@@ -0,0 +52,4 @@
+	if err != nil {
+		available := ListBuiltinPersonas()
+		return nil, fmt.Errorf("unknown built-in persona %q (available: %s)", name, strings.Join(available, ", "))
+	}

@@ -0,0 +76,4 @@
+	}
+	return names
+}
+

@@ -0,0 +81,4 @@
+	var p Persona
+	
+	// Determine format by extension or try YAML first (it's a superset of JSON)
+	ext := strings.ToLower(filepath.Ext(source))

@@ -0,0 +91,4 @@
+		if err := yaml.Unmarshal(data, &p); err != nil {
+			return nil, fmt.Errorf("parse persona %s: %w", source, err)
+		}
+	}

@@ -0,0 +53,4 @@
+	// Output format instructions (shared schema from prompt.go)
+	sb.WriteString("## Review Instructions\n\n")
+	sb.WriteString("CONTEXT:\n")
+	sb.WriteString("- You will receive the full content of modified files for reference, followed by the diff showing what changed.\n")

@@ -48,0 +75,4 @@
+	// Save and restore GITHUB_WORKSPACE
+	origWorkspace := os.Getenv("GITHUB_WORKSPACE")
+	defer os.Setenv("GITHUB_WORKSPACE", origWorkspace)
+

@@ -48,0 +93,4 @@
+			name:      "valid nested path",
+			workspace: tmpDir,
+			path:      "subdir/nested.json",
+			wantErr:   false,

@@ -2,2 +2,4 @@
 
 go 1.26.2
+
+require github.com/goccy/go-yaml v1.19.2

@@ -0,0 +15,4 @@
+var embeddedPersonas embed.FS
+
+// Persona defines a specialized review role with focused expertise.
+type Persona struct {

@@ -1,3 +1,5 @@
 module gitea.weiker.me/rodin/review-bot
 
 go 1.26.2
+

@@ -10,0 +22,4 @@
+	}
+}
+
+// FormatMarkdownWithDisplay formats a ReviewResult with separate display name and sentinel name.

@@ -48,0 +93,4 @@
+			name:      "valid nested path",
+			workspace: tmpDir,
+			path:      "subdir/nested.json",
+			wantErr:   false,

@@ -0,0 +73,4 @@
+output_format: |
+  For each finding:
+  - Severity: [CRITICAL|MAJOR|MINOR|NIT]
+  - Attack vector: How could this be exploited?

@@ -12,2 +33,2 @@
-	if reviewerName != "" {
-		title := strings.ToUpper(reviewerName[:1]) + reviewerName[1:]
+	// Use display name for header, or fall back to sentinel name
+	headerName := displayName

@@ -0,0 +56,4 @@
+// ListBuiltinPersonas returns the names of all built-in personas.
+// Returns an empty slice if the embedded directory cannot be read.
+func ListBuiltinPersonas() []string {
+	entries, err := embeddedPersonas.ReadDir("personas")

@@ -0,0 +94,4 @@
+	// DisplayName defaults to Name if not set
+	if p.DisplayName == "" {
+		p.DisplayName = p.Name
+	}

@@ -0,0 +59,4 @@
+	sb.WriteString("Your task:\n")
+	sb.WriteString("1. Review the diff for issues within YOUR focus areas only.\n")
+	sb.WriteString("2. Consider the CI status — if CI has failed, that is an automatic REQUEST_CHANGES regardless of code quality.\n")
+	sb.WriteString("3. Output your review as structured JSON (and ONLY JSON, no markdown fences or other text).\n\n")

@@ -332,0 +342,4 @@
+|---------|-------|
+| `security` | Vulnerabilities, auth bypass, secrets exposure, injection attacks |
+| `architect` | Design patterns, code organization, API contracts, testability |
+| `docs` | Documentation quality, API clarity, error messages |

@@ -332,0 +357,4 @@
+
+### Multiple Personas in Parallel
+
+```yaml

@@ -0,0 +317,4 @@
+
+### Finding 3: display_name vs reviewer-name
+Design says header shows "persona display name" but sentinel uses "reviewer-name". This is correct - they serve different purposes:
+- `display_name` → human-readable header ("Security Specialist Review")

@@ -10,0 +25,4 @@
+// FormatMarkdownWithDisplay formats a ReviewResult with separate display name and sentinel name.
+// Note: displayName is not HTML-escaped as Gitea sanitizes rendered Markdown.
+// Persona display names are controlled by repo owners (trusted input).
+// displayName is used for the header title, sentinelName is used for the cleanup sentinel.

@@ -0,0 +36,4 @@
+func LoadPersona(path string) (*Persona, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("read persona file %s: %w", path, err)