feat: rename working_dir→project_dir; git sandbox execution

- ClaudeConfig.WorkingDir → ProjectDir (json: project_dir)
- UnmarshalJSON fallback reads legacy working_dir from DB records
- New executions with project_dir clone into a temp sandbox via git clone --local
- Non-git project_dirs get git init + initial commit before clone
- After success: verify clean working tree, merge --ff-only back to project_dir, remove sandbox
- On failure/BLOCKED: sandbox preserved, path included in error message
- Resume executions run directly in project_dir (no re-clone)

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

3 files changed, 10 insertions, 10 deletions

diff --git a/internal/api/elaborate.go b/internal/api/elaborate.go
index 00f3297..e480e00 100644
--- a/internal/api/elaborate.go
+++ b/internal/api/elaborate.go
@@ -14,9 +14,9 @@ import (
 const elaborateTimeout = 30 * time.Second
 
 func buildElaboratePrompt(workDir string) string {
-	workDirLine := `    "working_dir":     string  — leave empty unless you have a specific reason to set it,`
+	workDirLine := `    "project_dir":     string  — leave empty unless you have a specific reason to set it,`
 	if workDir != "" {
-		workDirLine = fmt.Sprintf(`    "working_dir":     string  — use %q for tasks that operate on this codebase, empty string otherwise,`, workDir)
+		workDirLine = fmt.Sprintf(`    "project_dir":     string  — use %q for tasks that operate on this codebase, empty string otherwise,`, workDir)
 	}
 	return `You are a task configuration assistant for Claudomator, an AI task runner that executes tasks by running Claude as a subprocess.
 
@@ -53,7 +53,7 @@ type elaboratedTask struct {
 type elaboratedClaude struct {
 	Model        string   `json:"model"`
 	Instructions string   `json:"instructions"`
-	WorkingDir   string   `json:"working_dir"`
+	ProjectDir   string   `json:"project_dir"`
 	MaxBudgetUSD float64  `json:"max_budget_usd"`
 	AllowedTools []string `json:"allowed_tools"`
 }
@@ -87,7 +87,7 @@ func (s *Server) claudeBinaryPath() string {
 func (s *Server) handleElaborateTask(w http.ResponseWriter, r *http.Request) {
 	var input struct {
 		Prompt     string `json:"prompt"`
-		WorkingDir string `json:"working_dir"`
+		ProjectDir string `json:"project_dir"`
 	}
 	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
 		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid JSON: " + err.Error()})
@@ -99,8 +99,8 @@ func (s *Server) handleElaborateTask(w http.ResponseWriter, r *http.Request) {
 	}
 
 	workDir := s.workDir
-	if input.WorkingDir != "" {
-		workDir = input.WorkingDir
+	if input.ProjectDir != "" {
+		workDir = input.ProjectDir
 	}
 
 	ctx, cancel := context.WithTimeout(r.Context(), elaborateTimeout)
diff --git a/internal/api/elaborate_test.go b/internal/api/elaborate_test.go
index 52f7fdf..09f7fbe 100644
--- a/internal/api/elaborate_test.go
+++ b/internal/api/elaborate_test.go
@@ -56,7 +56,7 @@ func TestElaborateTask_Success(t *testing.T) {
 		Claude: elaboratedClaude{
 			Model:        "sonnet",
 			Instructions: "Run go test -race ./... and report results.",
-			WorkingDir:   "",
+			ProjectDir:   "",
 			MaxBudgetUSD: 0.5,
 			AllowedTools: []string{"Bash"},
 		},
diff --git a/internal/api/validate.go b/internal/api/validate.go
index d8ebde9..4b691a9 100644
--- a/internal/api/validate.go
+++ b/internal/api/validate.go
@@ -56,7 +56,7 @@ func (s *Server) handleValidateTask(w http.ResponseWriter, r *http.Request) {
 		Name  string `json:"name"`
 		Claude struct {
 			Instructions string   `json:"instructions"`
-			WorkingDir   string   `json:"working_dir"`
+			ProjectDir   string   `json:"project_dir"`
 			AllowedTools []string `json:"allowed_tools"`
 		} `json:"claude"`
 	}
@@ -74,8 +74,8 @@ func (s *Server) handleValidateTask(w http.ResponseWriter, r *http.Request) {
 	}
 
 	userMsg := fmt.Sprintf("Task name: %s\n\nInstructions:\n%s", input.Name, input.Claude.Instructions)
-	if input.Claude.WorkingDir != "" {
-		userMsg += fmt.Sprintf("\n\nWorking directory: %s", input.Claude.WorkingDir)
+	if input.Claude.ProjectDir != "" {
+		userMsg += fmt.Sprintf("\n\nWorking directory: %s", input.Claude.ProjectDir)
 	}
 	if len(input.Claude.AllowedTools) > 0 {
 		userMsg += fmt.Sprintf("\n\nAllowed tools: %v", input.Claude.AllowedTools)