Merge feat/container-execution into master

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

1 files changed, 0 insertions, 714 deletions

diff --git a/internal/executor/claude.go b/internal/executor/claude.go
deleted file mode 100644
index 6346aa8..0000000
--- a/internal/executor/claude.go
+++ /dev/null
@@ -1,714 +0,0 @@
-package executor
-
-import (
-	"bufio"
-	"context"
-	"encoding/json"
-	"fmt"
-	"io"
-	"log/slog"
-	"os"
-	"os/exec"
-	"path/filepath"
-	"strings"
-	"sync"
-	"syscall"
-	"time"
-
-	"github.com/thepeterstone/claudomator/internal/storage"
-	"github.com/thepeterstone/claudomator/internal/task"
-)
-
-// ClaudeRunner spawns the `claude` CLI in non-interactive mode.
-type ClaudeRunner struct {
-	BinaryPath string // defaults to "claude"
-	Logger     *slog.Logger
-	LogDir     string // base directory for execution logs
-	APIURL     string // base URL of the Claudomator API, passed to subprocesses
-	DropsDir   string // path to the drops directory, passed to subprocesses
-}
-
-// BlockedError is returned by Run when the agent wrote a question file and exited.
-// The pool transitions the task to BLOCKED and stores the question for the user.
-type BlockedError struct {
-	QuestionJSON string // raw JSON from the question file
-	SessionID    string // claude session to resume once the user answers
-	SandboxDir   string // preserved sandbox path; resume must run here so Claude finds its session files
-}
-
-func (e *BlockedError) Error() string { return fmt.Sprintf("task blocked: %s", e.QuestionJSON) }
-
-// ExecLogDir returns the log directory for the given execution ID.
-// Implements LogPather so the pool can persist paths before execution starts.
-func (r *ClaudeRunner) ExecLogDir(execID string) string {
-	if r.LogDir == "" {
-		return ""
-	}
-	return filepath.Join(r.LogDir, execID)
-}
-
-func (r *ClaudeRunner) binaryPath() string {
-	if r.BinaryPath != "" {
-		return r.BinaryPath
-	}
-	return "claude"
-}
-
-// Run executes a claude -p invocation, streaming output to log files.
-// It retries up to 3 times on rate-limit errors using exponential backoff.
-// If the agent writes a question file and exits, Run returns *BlockedError.
-//
-// When project_dir is set and this is not a resume execution, Run clones the
-// project into a temp sandbox, runs the agent there, then merges committed
-// changes back to project_dir. On failure the sandbox is preserved and its
-// path is included in the error.
-func (r *ClaudeRunner) Run(ctx context.Context, t *task.Task, e *storage.Execution) error {
-	projectDir := t.Agent.ProjectDir
-
-	// Validate project_dir exists when set.
-	if projectDir != "" {
-		if _, err := os.Stat(projectDir); err != nil {
-			return fmt.Errorf("project_dir %q: %w", projectDir, err)
-		}
-	}
-
-	// Setup log directory once; retries overwrite the log files.
-	logDir := r.ExecLogDir(e.ID)
-	if logDir == "" {
-		logDir = e.ID // fallback for tests without LogDir set
-	}
-	if err := os.MkdirAll(logDir, 0700); err != nil {
-		return fmt.Errorf("creating log dir: %w", err)
-	}
-	if e.StdoutPath == "" {
-		e.StdoutPath = filepath.Join(logDir, "stdout.log")
-		e.StderrPath = filepath.Join(logDir, "stderr.log")
-		e.ArtifactDir = logDir
-	}
-
-	// Pre-assign session ID so we can resume after a BLOCKED state.
-	// For resume executions, the claude session continues under the original
-	// session ID (the one passed to --resume). Using the new exec's own UUID
-	// would cause a second block-and-resume cycle to pass the wrong --resume
-	// argument.
-	if e.SessionID == "" {
-		if e.ResumeSessionID != "" {
-			e.SessionID = e.ResumeSessionID
-		} else {
-			e.SessionID = e.ID // reuse execution UUID as session UUID (both are UUIDs)
-		}
-	}
-
-	// For new (non-resume) executions with a project_dir, clone into a sandbox.
-	// Resume executions run in the preserved sandbox (e.SandboxDir) so Claude
-	// finds its session files under the same project slug. If no sandbox was
-	// preserved (e.g. task had no project_dir), fall back to project_dir.
-	var sandboxDir string
-	var startHEAD string
-	effectiveWorkingDir := projectDir
-	if e.ResumeSessionID != "" {
-		if e.SandboxDir != "" {
-			if _, statErr := os.Stat(e.SandboxDir); statErr == nil {
-				effectiveWorkingDir = e.SandboxDir
-			} else {
-				// Preserved sandbox was cleaned up (e.g. /tmp purge after reboot).
-				// Clone a fresh sandbox so the task can run rather than fail immediately.
-				r.Logger.Warn("preserved sandbox missing, cloning fresh", "sandbox", e.SandboxDir, "project_dir", projectDir)
-				e.SandboxDir = ""
-				if projectDir != "" {
-					var err error
-					sandboxDir, err = setupSandbox(t.Agent.ProjectDir, r.Logger)
-					if err != nil {
-						return fmt.Errorf("setting up sandbox: %w", err)
-					}
-
-					effectiveWorkingDir = sandboxDir
-					r.Logger.Info("fresh sandbox created for resume", "sandbox", sandboxDir, "project_dir", projectDir)
-				}
-			}
-		}
-	} else if projectDir != "" {
-		var err error
-		sandboxDir, err = setupSandbox(t.Agent.ProjectDir, r.Logger)
-		if err != nil {
-			return fmt.Errorf("setting up sandbox: %w", err)
-		}
-
-		effectiveWorkingDir = sandboxDir
-		r.Logger.Info("sandbox created", "sandbox", sandboxDir, "project_dir", projectDir)
-	}
-
-	if effectiveWorkingDir != "" {
-		// Capture the initial HEAD so we can identify new commits later.
-		headOut, _ := exec.Command("git", gitSafe("-C", effectiveWorkingDir, "rev-parse", "HEAD")...).Output()
-		startHEAD = strings.TrimSpace(string(headOut))
-	}
-
-	questionFile := filepath.Join(logDir, "question.json")
-	args := r.buildArgs(t, e, questionFile)
-
-	attempt := 0
-	err := runWithBackoff(ctx, 3, 5*time.Second, func() error {
-		if attempt > 0 {
-			delay := 5 * time.Second * (1 << (attempt - 1))
-			r.Logger.Warn("rate-limited by Claude API, retrying",
-				"attempt", attempt,
-				"delay", delay,
-			)
-		}
-		attempt++
-		return r.execOnce(ctx, args, effectiveWorkingDir, projectDir, e)
-	})
-	if err != nil {
-		if sandboxDir != "" {
-			return fmt.Errorf("%w (sandbox preserved at %s)", err, sandboxDir)
-		}
-		return err
-	}
-
-	// Check whether the agent left a question before exiting.
-	data, readErr := os.ReadFile(questionFile)
-	if readErr == nil {
-		os.Remove(questionFile) // consumed
-		questionJSON := strings.TrimSpace(string(data))
-		// If the agent wrote a completion report instead of a real question,
-		// extract the text as the summary and fall through to normal completion.
-		if isCompletionReport(questionJSON) {
-			r.Logger.Info("treating question file as completion report", "taskID", e.TaskID)
-			e.Summary = extractQuestionText(questionJSON)
-		} else {
-			// Preserve sandbox on BLOCKED — agent may have partial work and its
-			// Claude session files are stored under the sandbox's project slug.
-			// The resume execution must run in the same directory.
-			return &BlockedError{QuestionJSON: questionJSON, SessionID: e.SessionID, SandboxDir: sandboxDir}
-		}
-	}
-
-	// Read agent summary if written.
-	summaryFile := filepath.Join(logDir, "summary.txt")
-	if summaryData, readErr := os.ReadFile(summaryFile); readErr == nil {
-		os.Remove(summaryFile) // consumed
-		e.Summary = strings.TrimSpace(string(summaryData))
-	}
-
-	// Merge sandbox back to project_dir and clean up.
-	if sandboxDir != "" {
-		if mergeErr := teardownSandbox(projectDir, sandboxDir, startHEAD, r.Logger, e); mergeErr != nil {
-			return fmt.Errorf("sandbox teardown: %w (sandbox preserved at %s)", mergeErr, sandboxDir)
-		}
-	}
-	return nil
-}
-
-// isCompletionReport returns true when a question-file JSON looks like a
-// completion report rather than a real user question. Heuristic: no options
-// (or empty options) and no "?" anywhere in the text.
-func isCompletionReport(questionJSON string) bool {
-	var q struct {
-		Text    string   `json:"text"`
-		Options []string `json:"options"`
-	}
-	if err := json.Unmarshal([]byte(questionJSON), &q); err != nil {
-		return false
-	}
-	return len(q.Options) == 0 && !strings.Contains(q.Text, "?")
-}
-
-// extractQuestionText returns the "text" field from a question-file JSON, or
-// the raw string if parsing fails.
-func extractQuestionText(questionJSON string) string {
-	var q struct {
-		Text string `json:"text"`
-	}
-	if err := json.Unmarshal([]byte(questionJSON), &q); err != nil {
-		return questionJSON
-	}
-	return strings.TrimSpace(q.Text)
-}
-
-// gitSafe returns git arguments that prepend "-c safe.directory=*" so that
-// commands succeed regardless of the repository owner. This is needed when
-// claudomator operates on project directories owned by a different OS user.
-func gitSafe(args ...string) []string {
-	return append([]string{"-c", "safe.directory=*"}, args...)
-}
-
-// sandboxCloneSource returns the URL to clone the sandbox from. It prefers a
-// remote named "local" (a local bare repo that accepts pushes cleanly), then
-// falls back to "origin", then to the working copy path itself.
-func sandboxCloneSource(projectDir string) string {
-	// Prefer "local" remote, but only if it points to a local path (accepts pushes).
-	if out, err := exec.Command("git", gitSafe("-C", projectDir, "remote", "get-url", "local")...).Output(); err == nil {
-		u := strings.TrimSpace(string(out))
-		if u != "" && (strings.HasPrefix(u, "/") || strings.HasPrefix(u, "file://")) {
-			return u
-		}
-	}
-	// Fall back to "origin" — any URL scheme is acceptable for cloning.
-	if out, err := exec.Command("git", gitSafe("-C", projectDir, "remote", "get-url", "origin")...).Output(); err == nil {
-		if u := strings.TrimSpace(string(out)); u != "" {
-			return u
-		}
-	}
-	return projectDir
-}
-
-// setupSandbox prepares a temporary git clone of projectDir.
-// If projectDir is not a git repo it is initialised with an initial commit first.
-func setupSandbox(projectDir string, logger *slog.Logger) (string, error) {
-	// Ensure projectDir is a git repo; initialise if not.
-	if err := exec.Command("git", gitSafe("-C", projectDir, "rev-parse", "--git-dir")...).Run(); err != nil {
-		cmds := [][]string{
-			gitSafe("-C", projectDir, "init"),
-			gitSafe("-C", projectDir, "add", "-A"),
-			gitSafe("-C", projectDir, "commit", "--allow-empty", "-m", "chore: initial commit"),
-		}
-		for _, args := range cmds {
-			if out, err := exec.Command("git", args...).CombinedOutput(); err != nil { //nolint:gosec
-				return "", fmt.Errorf("git init %s: %w\n%s", projectDir, err, out)
-			}
-		}
-	}
-
-	src := sandboxCloneSource(projectDir)
-
-	tempDir, err := os.MkdirTemp("", "claudomator-sandbox-*")
-	if err != nil {
-		return "", fmt.Errorf("creating sandbox dir: %w", err)
-	}
-	// git clone requires the target to not exist; remove the placeholder first.
-	if err := os.Remove(tempDir); err != nil {
-		return "", fmt.Errorf("removing temp dir placeholder: %w", err)
-	}
-	out, err := exec.Command("git", gitSafe("clone", "--no-hardlinks", src, tempDir)...).CombinedOutput()
-	if err != nil {
-		return "", fmt.Errorf("git clone: %w\n%s", err, out)
-	}
-	return tempDir, nil
-}
-
-// teardownSandbox verifies the sandbox is clean and pushes new commits to the
-// canonical bare repo. If the push is rejected because another task pushed
-// concurrently, it fetches and rebases then retries once.
-//
-// The working copy (projectDir) is NOT updated automatically — it is the
-// developer's workspace and is pulled manually. This avoids permission errors
-// from mixed-owner .git/objects directories.
-func teardownSandbox(projectDir, sandboxDir, startHEAD string, logger *slog.Logger, execRecord *storage.Execution) error {
-	// Automatically commit uncommitted changes.
-	out, err := exec.Command("git", "-C", sandboxDir, "status", "--porcelain").Output()
-	if err != nil {
-		return fmt.Errorf("git status: %w", err)
-	}
-	if len(strings.TrimSpace(string(out))) > 0 {
-		logger.Info("autocommitting uncommitted changes", "sandbox", sandboxDir)
-
-		// Run build before autocommitting.
-		if _, err := os.Stat(filepath.Join(sandboxDir, "Makefile")); err == nil {
-			logger.Info("running 'make build' before autocommit", "sandbox", sandboxDir)
-			if buildOut, buildErr := exec.Command("make", "-C", sandboxDir, "build").CombinedOutput(); buildErr != nil {
-				return fmt.Errorf("build failed before autocommit: %w\n%s", buildErr, buildOut)
-			}
-		} else if _, err := os.Stat(filepath.Join(sandboxDir, "gradlew")); err == nil {
-			logger.Info("running './gradlew build' before autocommit", "sandbox", sandboxDir)
-			cmd := exec.Command("./gradlew", "build")
-			cmd.Dir = sandboxDir
-			if buildOut, buildErr := cmd.CombinedOutput(); buildErr != nil {
-				return fmt.Errorf("build failed before autocommit: %w\n%s", buildErr, buildOut)
-			}
-		} else if _, err := os.Stat(filepath.Join(sandboxDir, "go.mod")); err == nil {
-			logger.Info("running 'go build ./...' before autocommit", "sandbox", sandboxDir)
-			cmd := exec.Command("go", "build", "./...")
-			cmd.Dir = sandboxDir
-			if buildOut, buildErr := cmd.CombinedOutput(); buildErr != nil {
-				return fmt.Errorf("build failed before autocommit: %w\n%s", buildErr, buildOut)
-			}
-		}
-
-		cmds := [][]string{
-			gitSafe("-C", sandboxDir, "add", "-A"),
-			gitSafe("-C", sandboxDir, "commit", "-m", "chore: autocommit uncommitted changes"),
-		}
-		for _, args := range cmds {
-			if out, err := exec.Command("git", args...).CombinedOutput(); err != nil {
-				return fmt.Errorf("autocommit failed (%v): %w\n%s", args, err, out)
-			}
-		}
-	}
-
-	// Capture commits before pushing/deleting.
-	// Use startHEAD..HEAD to find all commits made during this execution.
-	logRange := "origin/HEAD..HEAD"
-	if startHEAD != "" && startHEAD != "HEAD" {
-		logRange = startHEAD + "..HEAD"
-	}
-
-	logCmd := exec.Command("git", gitSafe("-C", sandboxDir, "log", logRange, "--pretty=format:%H|%s")...)
-	logOut, logErr := logCmd.CombinedOutput()
-	if logErr == nil {
-		lines := strings.Split(strings.TrimSpace(string(logOut)), "\n")
-		logger.Debug("captured commits", "count", len(lines), "range", logRange)
-		for _, line := range lines {
-			if line == "" {
-				continue
-			}
-			parts := strings.SplitN(line, "|", 2)
-			if len(parts) == 2 {
-				execRecord.Commits = append(execRecord.Commits, task.GitCommit{
-					Hash:    parts[0],
-					Message: parts[1],
-				})
-			}
-		}
-	} else {
-		logger.Warn("failed to capture commits", "err", logErr, "range", logRange, "output", string(logOut))
-	}
-
-	// Check whether there are any new commits to push.
-	ahead, err := exec.Command("git", gitSafe("-C", sandboxDir, "rev-list", "--count", logRange)...).Output()
-	if err != nil {
-		logger.Warn("could not determine commits ahead of origin; proceeding", "err", err, "range", logRange)
-	}
-	if strings.TrimSpace(string(ahead)) == "0" {
-		os.RemoveAll(sandboxDir)
-		return nil
-	}
-
-	// Push from sandbox → bare repo (sandbox's origin is the bare repo).
-	if out, err := exec.Command("git", "-C", sandboxDir, "push", "origin", "HEAD").CombinedOutput(); err != nil {
-		// If rejected due to concurrent push, fetch+rebase and retry once.
-		if strings.Contains(string(out), "fetch first") || strings.Contains(string(out), "non-fast-forward") {
-			logger.Info("push rejected (concurrent task); rebasing and retrying", "sandbox", sandboxDir)
-			if out2, err2 := exec.Command("git", "-C", sandboxDir, "pull", "--rebase", "origin", "master").CombinedOutput(); err2 != nil {
-				return fmt.Errorf("git rebase before retry push: %w\n%s", err2, out2)
-			}
-			// Re-capture commits after rebase (hashes might have changed)
-			execRecord.Commits = nil
-			logOut, logErr = exec.Command("git", "-C", sandboxDir, "log", logRange, "--pretty=format:%H|%s").Output()
-			if logErr == nil {
-				lines := strings.Split(strings.TrimSpace(string(logOut)), "\n")
-				for _, line := range lines {
-					parts := strings.SplitN(line, "|", 2)
-					if len(parts) == 2 {
-						execRecord.Commits = append(execRecord.Commits, task.GitCommit{
-							Hash:    parts[0],
-							Message: parts[1],
-						})
-					}
-				}
-			}
-
-			if out3, err3 := exec.Command("git", "-C", sandboxDir, "push", "origin", "HEAD").CombinedOutput(); err3 != nil {
-				return fmt.Errorf("git push to origin (after rebase): %w\n%s", err3, out3)
-			}
-		} else {
-			return fmt.Errorf("git push to origin: %w\n%s", err, out)
-		}
-	}
-
-	logger.Info("sandbox pushed to bare repo", "sandbox", sandboxDir)
-	os.RemoveAll(sandboxDir)
-	return nil
-}
-
-// execOnce runs the claude subprocess once, streaming output to e's log paths.
-func (r *ClaudeRunner) execOnce(ctx context.Context, args []string, workingDir, projectDir string, e *storage.Execution) error {
-	cmd := exec.CommandContext(ctx, r.binaryPath(), args...)
-	cmd.Env = append(os.Environ(),
-		"CLAUDOMATOR_API_URL="+r.APIURL,
-		"CLAUDOMATOR_TASK_ID="+e.TaskID,
-		"CLAUDOMATOR_PROJECT_DIR="+projectDir,
-		"CLAUDOMATOR_QUESTION_FILE="+filepath.Join(e.ArtifactDir, "question.json"),
-		"CLAUDOMATOR_SUMMARY_FILE="+filepath.Join(e.ArtifactDir, "summary.txt"),
-		"CLAUDOMATOR_DROP_DIR="+r.DropsDir,
-	)
-	// Put the subprocess in its own process group so we can SIGKILL the entire
-	// group (MCP servers, bash children, etc.) on cancellation.
-	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
-	if workingDir != "" {
-		cmd.Dir = workingDir
-	}
-
-	stdoutFile, err := os.Create(e.StdoutPath)
-	if err != nil {
-		return fmt.Errorf("creating stdout log: %w", err)
-	}
-	defer stdoutFile.Close()
-
-	stderrFile, err := os.Create(e.StderrPath)
-	if err != nil {
-		return fmt.Errorf("creating stderr log: %w", err)
-	}
-	defer stderrFile.Close()
-
-	// Use os.Pipe for stdout so we own the read-end lifetime.
-	// cmd.StdoutPipe() would add the read-end to closeAfterWait, causing
-	// cmd.Wait() to close it before our goroutine finishes reading.
-	stdoutR, stdoutW, err := os.Pipe()
-	if err != nil {
-		return fmt.Errorf("creating stdout pipe: %w", err)
-	}
-	cmd.Stdout = stdoutW // *os.File — not added to closeAfterStart/Wait
-	cmd.Stderr = stderrFile
-
-	if err := cmd.Start(); err != nil {
-		stdoutW.Close()
-		stdoutR.Close()
-		return fmt.Errorf("starting claude: %w", err)
-	}
-	// Close our write-end immediately; the subprocess holds its own copy.
-	// The goroutine below gets EOF when the subprocess exits.
-	stdoutW.Close()
-
-	// killDone is closed when cmd.Wait() returns, stopping the pgid-kill goroutine.
-	//
-	// Safety: this goroutine cannot block indefinitely. The select has two arms:
-	//   • ctx.Done() — fires if the caller cancels (e.g. timeout, user cancel).
-	//     The goroutine sends SIGKILL and exits immediately.
-	//   • killDone — closed by close(killDone) below, immediately after cmd.Wait()
-	//     returns. This fires when the process exits for any reason (natural exit,
-	//     SIGKILL from the ctx arm, or any other signal). The goroutine exits without
-	//     doing anything.
-	//
-	// Therefore: for a task that completes normally with a long-lived (non-cancelled)
-	// context, the killDone arm fires and the goroutine exits. There is no path where
-	// this goroutine outlives execOnce().
-	killDone := make(chan struct{})
-	go func() {
-		select {
-		case <-ctx.Done():
-			// SIGKILL the entire process group to reap orphan children.
-			syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
-		case <-killDone:
-		}
-	}()
-
-	// Stream stdout to the log file and parse cost/errors.
-	// wg ensures costUSD and streamErr are fully written before we read them after cmd.Wait().
-	var costUSD float64
-	var streamErr error
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		costUSD, streamErr = parseStream(stdoutR, stdoutFile, r.Logger)
-		stdoutR.Close()
-	}()
-
-	waitErr := cmd.Wait()
-	close(killDone) // stop the pgid-kill goroutine
-	wg.Wait()       // drain remaining stdout before reading costUSD/streamErr
-
-	e.CostUSD = costUSD
-
-	if waitErr != nil {
-		if exitErr, ok := waitErr.(*exec.ExitError); ok {
-			e.ExitCode = exitErr.ExitCode()
-		}
-		// If the stream captured a rate-limit or quota message, return it
-		// so callers can distinguish it from a generic exit-status failure.
-		if isRateLimitError(streamErr) || isQuotaExhausted(streamErr) {
-			return streamErr
-		}
-		if tail := tailFile(e.StderrPath, 20); tail != "" {
-			return fmt.Errorf("claude exited with error: %w\nstderr:\n%s", waitErr, tail)
-		}
-		return fmt.Errorf("claude exited with error: %w", waitErr)
-	}
-
-	e.ExitCode = 0
-	if streamErr != nil {
-		return streamErr
-	}
-	return nil
-}
-
-func (r *ClaudeRunner) buildArgs(t *task.Task, e *storage.Execution, questionFile string) []string {
-	// Resume execution: the agent already has context; just deliver the answer.
-	if e.ResumeSessionID != "" {
-		args := []string{
-			"-p", e.ResumeAnswer,
-			"--resume", e.ResumeSessionID,
-			"--output-format", "stream-json",
-			"--verbose",
-		}
-		permMode := t.Agent.PermissionMode
-		if permMode == "" {
-			permMode = "bypassPermissions"
-		}
-		args = append(args, "--permission-mode", permMode)
-		if t.Agent.Model != "" {
-			args = append(args, "--model", t.Agent.Model)
-		}
-		return args
-	}
-
-	instructions := t.Agent.Instructions
-	allowedTools := t.Agent.AllowedTools
-
-	if !t.Agent.SkipPlanning {
-		instructions = withPlanningPreamble(instructions)
-		// Ensure Bash is available so the agent can POST subtasks and ask questions.
-		hasBash := false
-		for _, tool := range allowedTools {
-			if tool == "Bash" {
-				hasBash = true
-				break
-			}
-		}
-		if !hasBash {
-			allowedTools = append(allowedTools, "Bash")
-		}
-	}
-
-	args := []string{
-		"-p", instructions,
-		"--session-id", e.SessionID,
-		"--output-format", "stream-json",
-		"--verbose",
-	}
-
-	if t.Agent.Model != "" {
-		args = append(args, "--model", t.Agent.Model)
-	}
-	if t.Agent.MaxBudgetUSD > 0 {
-		args = append(args, "--max-budget-usd", fmt.Sprintf("%.2f", t.Agent.MaxBudgetUSD))
-	}
-	// Default to bypassPermissions — claudomator runs tasks unattended, so
-	// prompting for write access would always stall execution. Tasks that need
-	// a more restrictive mode can set permission_mode explicitly.
-	permMode := t.Agent.PermissionMode
-	if permMode == "" {
-		permMode = "bypassPermissions"
-	}
-	args = append(args, "--permission-mode", permMode)
-	if t.Agent.SystemPromptAppend != "" {
-		args = append(args, "--append-system-prompt", t.Agent.SystemPromptAppend)
-	}
-	for _, tool := range allowedTools {
-		args = append(args, "--allowedTools", tool)
-	}
-	for _, tool := range t.Agent.DisallowedTools {
-		args = append(args, "--disallowedTools", tool)
-	}
-	for _, f := range t.Agent.ContextFiles {
-		args = append(args, "--add-dir", f)
-	}
-	args = append(args, t.Agent.AdditionalArgs...)
-
-	return args
-}
-
-// parseStream reads streaming JSON from claude, writes to w, and returns
-// (costUSD, error). error is non-nil if the stream signals task failure:
-// - result message has is_error:true
-// - a tool_result was denied due to missing permissions
-func parseStream(r io.Reader, w io.Writer, logger *slog.Logger) (float64, error) {
-	tee := io.TeeReader(r, w)
-	scanner := bufio.NewScanner(tee)
-	scanner.Buffer(make([]byte, 1024*1024), 1024*1024) // 1MB buffer for large lines
-
-	var totalCost float64
-	var streamErr error
-
-	for scanner.Scan() {
-		line := scanner.Bytes()
-		var msg map[string]interface{}
-		if err := json.Unmarshal(line, &msg); err != nil {
-			continue
-		}
-
-		msgType, _ := msg["type"].(string)
-		switch msgType {
-		case "rate_limit_event":
-			if info, ok := msg["rate_limit_info"].(map[string]interface{}); ok {
-				status, _ := info["status"].(string)
-				if status == "rejected" {
-					streamErr = fmt.Errorf("claude rate limit reached (rejected): %v", msg)
-					// Immediately break since we can't continue anyway
-					break
-				}
-			}
-		case "assistant":
-			if errStr, ok := msg["error"].(string); ok && errStr == "rate_limit" {
-				streamErr = fmt.Errorf("claude rate limit reached: %v", msg)
-			}
-		case "result":
-			if isErr, _ := msg["is_error"].(bool); isErr {
-				result, _ := msg["result"].(string)
-				if result != "" {
-					streamErr = fmt.Errorf("claude task failed: %s", result)
-				} else {
-					streamErr = fmt.Errorf("claude task failed (is_error=true in result)")
-				}
-			}
-			// Prefer total_cost_usd from result message; fall through to legacy check below.
-			if cost, ok := msg["total_cost_usd"].(float64); ok {
-				totalCost = cost
-			}
-		case "user":
-			// Detect permission-denial tool_results. These occur when permission_mode
-			// is not bypassPermissions and claude exits 0 without completing its task.
-			if err := permissionDenialError(msg); err != nil && streamErr == nil {
-				streamErr = err
-			}
-		}
-
-		// Legacy cost field used by older claude versions.
-		if cost, ok := msg["cost_usd"].(float64); ok {
-			totalCost = cost
-		}
-	}
-
-	return totalCost, streamErr
-}
-
-// permissionDenialError inspects a "user" stream message for tool_result entries
-// that were denied due to missing permissions. Returns an error if found.
-func permissionDenialError(msg map[string]interface{}) error {
-	message, ok := msg["message"].(map[string]interface{})
-	if !ok {
-		return nil
-	}
-	content, ok := message["content"].([]interface{})
-	if !ok {
-		return nil
-	}
-	for _, item := range content {
-		itemMap, ok := item.(map[string]interface{})
-		if !ok {
-			continue
-		}
-		if itemMap["type"] != "tool_result" {
-			continue
-		}
-		if isErr, _ := itemMap["is_error"].(bool); !isErr {
-			continue
-		}
-		text, _ := itemMap["content"].(string)
-		if strings.Contains(text, "requested permissions") || strings.Contains(text, "haven't granted") {
-			return fmt.Errorf("permission denied by host: %s", text)
-		}
-	}
-	return nil
-}
-
-// tailFile returns the last n lines of the file at path, or empty string if
-// the file cannot be read. Used to surface subprocess stderr on failure.
-func tailFile(path string, n int) string {
-	f, err := os.Open(path)
-	if err != nil {
-		return ""
-	}
-	defer f.Close()
-
-	var lines []string
-	scanner := bufio.NewScanner(f)
-	for scanner.Scan() {
-		lines = append(lines, scanner.Text())
-		if len(lines) > n {
-			lines = lines[1:]
-		}
-	}
-	return strings.Join(lines, "\n")
-}