feat: add trace control — hawk can enable/disable/status trace on user request

trace remains fully independent (own repo, own install, works with any agent).
hawk provides /trace-enable, /trace-disable, /trace-status as convenience.
hawk NEVER auto-enables trace — user must explicitly opt in.

Author: Patel230

sessioncapture/INSTALL.md

@@ -0,0 +1,97 @@
+// Package sessioncapture provides hawk's interface to trace.
+//
+// trace is a fully independent tool (own repo, own binary, works with any agent).
+// hawk can optionally manage it via slash commands:
+//   /trace-enable   — enable session capture
+//   /trace-disable  — disable session capture
+//   /trace-status   — show capture status
+//
+// hawk NEVER auto-enables trace. The user must explicitly opt in.
+package sessioncapture
+
+import (
+	"fmt"
+	"os/exec"
+	"path/filepath"
+	"os"
+	"strings"
+)
+
+// TraceControl lets hawk manage trace when the user asks.
+// trace remains independent — hawk just provides UI convenience.
+type TraceControl struct {
+	ProjectDir string
+}
+
+// NewTraceControl creates a controller for the given project.
+func NewTraceControl(projectDir string) *TraceControl {
+	return &TraceControl{ProjectDir: projectDir}
+}
+
+// IsInstalled checks if trace binary exists in PATH.
+func (tc *TraceControl) IsInstalled() bool {
+	_, err := exec.LookPath("trace")
+	return err == nil
+}
+
+// IsEnabled checks if trace is active in this project.
+func (tc *TraceControl) IsEnabled() bool {
+	settingsPath := filepath.Join(tc.ProjectDir, ".trace", "settings.json")
+	_, err := os.Stat(settingsPath)
+	return err == nil
+}
+
+// Enable activates trace for this project. User must explicitly call this.
+func (tc *TraceControl) Enable() (string, error) {
+	if !tc.IsInstalled() {
+		return "", fmt.Errorf("trace is not installed. Install with: brew install GrayCodeAI/tap/trace")
+	}
+	if tc.IsEnabled() {
+		return "Session capture is already enabled.", nil
+	}
+
+	cmd := exec.Command("trace", "enable", "--agent", "hawk")
+	cmd.Dir = tc.ProjectDir
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return "", fmt.Errorf("failed to enable trace: %s", strings.TrimSpace(string(output)))
+	}
+	return "Session capture enabled. All future sessions will be recorded.", nil
+}
+
+// Disable deactivates trace for this project. User must explicitly call this.
+func (tc *TraceControl) Disable() (string, error) {
+	if !tc.IsInstalled() {
+		return "trace is not installed — nothing to disable.", nil
+	}
+	if !tc.IsEnabled() {
+		return "Session capture is already disabled.", nil
+	}
+
+	cmd := exec.Command("trace", "disable")
+	cmd.Dir = tc.ProjectDir
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return "", fmt.Errorf("failed to disable trace: %s", strings.TrimSpace(string(output)))
+	}
+	return "Session capture disabled. Sessions will no longer be recorded.", nil
+}
+
+// Status returns current trace state for display in hawk.
+func (tc *TraceControl) Status() string {
+	if !tc.IsInstalled() {
+		return "Session capture: not available (trace not installed)\n  Install: brew install GrayCodeAI/tap/trace"
+	}
+	if !tc.IsEnabled() {
+		return "Session capture: disabled\n  Enable: /trace-enable"
+	}
+
+	// Get detailed status from trace
+	cmd := exec.Command("trace", "status")
+	cmd.Dir = tc.ProjectDir
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return "Session capture: enabled (running)"
+	}
+	return "Session capture: enabled\n" + strings.TrimSpace(string(output))
+}