feat(tdd): inject session history into green and refactor worker prompts

Adds SessionsDir to tdd.Config, session_id to tool input schemas, and a
prependHistory method that reads the session JSONL log and prepends a
formatted history block to the task prompt before worker invocation.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cmd/supervisor/main.go

@@ -67,6 +67,7 @@ func main() {
 		SkillPrompt:  string(tddPrompt),
 		DefaultModel: models.Resolve("tdd", ""),
 		ExecutorFn:   executor.Run,
+		SessionsDir:  cfg.SessionsDir,
 	}))
 	reg.Register(brain.New(brain.Config{
 		IngestBaseURL: cfg.IngestBaseURL,

internal/skills/tdd/handlers.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 
 	iexec "github.com/mathiasbq/supervisor/internal/exec"
+	"github.com/mathiasbq/supervisor/internal/session"
 )
 
 func (s *Skill) Handle(ctx context.Context, tool string, args json.RawMessage) (json.RawMessage, error) {
@@ -51,6 +52,7 @@ type greenArgs struct {
 	TestPath    string `json:"test_path"`
 	Model       string `json:"model"`
 	TestCmd     string `json:"test_cmd"`
+	SessionID   string `json:"session_id"`
 }
 
 func (s *Skill) handleGreen(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
@@ -68,6 +70,7 @@ func (s *Skill) handleGreen(ctx context.Context, raw json.RawMessage) (json.RawM
 		"phase: green\nproject_root: %s\ntest_path: %s\nmodel: %s\ntest_cmd: %s",
 		args.ProjectRoot, args.TestPath, s.resolveModel(args.Model), args.TestCmd,
 	)
+	task = s.prependHistory(args.SessionID, "green", task)
 	return s.execute(ctx, task)
 }
 
@@ -77,6 +80,7 @@ type refactorArgs struct {
 	ImplPath    string `json:"impl_path"`
 	Model       string `json:"model"`
 	TestCmd     string `json:"test_cmd"`
+	SessionID   string `json:"session_id"`
 }
 
 func (s *Skill) handleRefactor(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
@@ -97,9 +101,25 @@ func (s *Skill) handleRefactor(ctx context.Context, raw json.RawMessage) (json.R
 		"phase: refactor\nproject_root: %s\ntest_path: %s\nimpl_path: %s\nmodel: %s\ntest_cmd: %s",
 		args.ProjectRoot, args.TestPath, args.ImplPath, s.resolveModel(args.Model), args.TestCmd,
 	)
+	task = s.prependHistory(args.SessionID, "refactor", task)
 	return s.execute(ctx, task)
 }
 
+func (s *Skill) prependHistory(sessionID, currentPhase, task string) string {
+	if sessionID == "" || s.cfg.SessionsDir == "" {
+		return task
+	}
+	entries, err := session.Read(s.cfg.SessionsDir, sessionID)
+	if err != nil || len(entries) == 0 {
+		return task
+	}
+	history := session.FormatHistory(entries, currentPhase)
+	if history == "" {
+		return task
+	}
+	return history + "\n---\n\n" + task
+}
+
 func (s *Skill) resolveModel(override string) string {
 	if override != "" {
 		return override

internal/skills/tdd/handlers_test.go

@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 	"testing"
 
+	iexec "github.com/mathiasbq/supervisor/internal/exec"
+	"github.com/mathiasbq/supervisor/internal/session"
 	"github.com/mathiasbq/supervisor/internal/skills/tdd"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -41,5 +43,43 @@ func TestTDDRedRequiresSpec(t *testing.T) {
 	assert.ErrorContains(t, err, "spec")
 }
 
+func TestTDDGreenInjectsSessionHistory(t *testing.T) {
+	sessDir := t.TempDir()
+	require.NoError(t, session.Append(sessDir, "sess-1", session.Entry{
+		SessionID: "sess-1", Skill: "tdd", Phase: "red", FinalStatus: "pass",
+		FilePath: "internal/foo/foo_test.go",
+		Message:  "wrote failing test for Foo",
+	}))
+
+	var capturedPrompt string
+	fakeFn := func(_ context.Context, req iexec.Request) (iexec.Result, error) {
+		capturedPrompt = req.TaskPrompt
+		return iexec.Result{Status: "pass", Phase: "green", Skill: "tdd", Verified: true, ModelUsed: "self", Message: "ok"}, nil
+	}
+
+	sk := tdd.New(tdd.Config{SkillPrompt: "tdd", ExecutorFn: fakeFn, SessionsDir: sessDir})
+	_, err := sk.Handle(context.Background(), "tdd_green", json.RawMessage(
+		`{"project_root":"/tmp","test_path":"internal/foo/foo_test.go","test_cmd":"go test ./...","session_id":"sess-1"}`,
+	))
+	require.NoError(t, err)
+	assert.Contains(t, capturedPrompt, "## Session history")
+	assert.Contains(t, capturedPrompt, "wrote failing test for Foo")
+}
+
+func TestTDDGreenNoHistoryWhenSessionIDEmpty(t *testing.T) {
+	var capturedPrompt string
+	fakeFn := func(_ context.Context, req iexec.Request) (iexec.Result, error) {
+		capturedPrompt = req.TaskPrompt
+		return iexec.Result{Status: "pass", Phase: "green", Skill: "tdd", Verified: true, ModelUsed: "self", Message: "ok"}, nil
+	}
+
+	sk := tdd.New(tdd.Config{SkillPrompt: "tdd", ExecutorFn: fakeFn, SessionsDir: t.TempDir()})
+	_, err := sk.Handle(context.Background(), "tdd_green", json.RawMessage(
+		`{"project_root":"/tmp","test_path":"internal/foo/foo_test.go"}`,
+	))
+	require.NoError(t, err)
+	assert.NotContains(t, capturedPrompt, "## Session history")
+}
+
 // Ensure require is used (avoids import error).
 var _ = require.New

internal/skills/tdd/skill.go

@@ -16,6 +16,7 @@ type Config struct {
 	SkillPrompt  string
 	ExecutorFn   ExecutorFn // nil = no executor (tests that don't reach execute())
 	DefaultModel string
+	SessionsDir  string // optional: path to brain/sessions/ for history injection
 }
 
 type Skill struct {
@@ -63,6 +64,7 @@ func (s *Skill) Tools() []registry.ToolDef {
 					"test_path":    strProp,
 					"model":        strProp,
 					"test_cmd":     strProp,
+					"session_id":   strProp,
 				},
 			),
 		},
@@ -77,6 +79,7 @@ func (s *Skill) Tools() []registry.ToolDef {
 					"impl_path":    strProp,
 					"model":        strProp,
 					"test_cmd":     strProp,
+					"session_id":   strProp,
 				},
 			),
 		},