feat: implement 6-phase evolution pipeline (plan, implement, pr, review, merge, communicate)

Add RunPRPhase, RunReviewPhase, and RunMergePhase to the evolution engine,
matching the 6 phases advertised on the website. Update evolve.sh to call
all 6 phases sequentially, removing the duplicate shell-based PR/review/merge
block that previously duplicated logic from the engine.

Author: Patel230

cmd/iterate/main_mode.go

@@ -148,6 +148,30 @@ func runEvolutionPhase(ctx context.Context, f mainFlags, p iteragent.Provider, e
 		}
 		logger.Info("implement phase complete")
 		return nil
+	case "pr":
+		logger.Info("running PR phase")
+		if err := engine.RunPRPhase(ctx); err != nil {
+			logger.Error("PR phase failed", "err", err)
+			os.Exit(1)
+		}
+		logger.Info("PR phase complete")
+		return nil
+	case "review":
+		logger.Info("running review phase")
+		if err := engine.RunReviewPhase(ctx, p); err != nil {
+			logger.Error("review phase failed", "err", err)
+			os.Exit(1)
+		}
+		logger.Info("review phase complete")
+		return nil
+	case "merge":
+		logger.Info("running merge phase")
+		if err := engine.RunMergePhase(ctx); err != nil {
+			logger.Error("merge phase failed", "err", err)
+			os.Exit(1)
+		}
+		logger.Info("merge phase complete")
+		return nil
 	case "communicate":
 		logger.Info("running communicate phase")
 		if err := engine.RunCommunicatePhase(ctx, p); err != nil {

internal/evolution/phases_pr.go

@@ -0,0 +1,136 @@
+package evolution
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	iteragent "github.com/GrayCodeAI/iteragent"
+)
+
+// RunPRPhase creates a feature branch from the current HEAD, pushes it, and opens a PR.
+// It is designed to run after RunImplementPhase has already committed changes to main.
+func (e *Engine) RunPRPhase(ctx context.Context) error {
+	ctx, cancel := withTimeout(ctx)
+	defer cancel()
+
+	day := e.readDayCount()
+
+	// Sync with remote before branching.
+	if out, err := e.runTool(ctx, "bash", map[string]string{
+		"cmd": "git pull --rebase origin main",
+	}); err != nil {
+		e.logger.Warn("pull rebase failed, continuing", "err", err, "output", out)
+	}
+
+	// Skip if nothing has changed relative to origin/main.
+	out, _ := e.runTool(ctx, "bash", map[string]string{
+		"cmd": "git diff origin/main HEAD --stat",
+	})
+	if strings.TrimSpace(out) == "" {
+		e.logger.Info("no changes vs origin/main — skipping PR creation")
+		return nil
+	}
+
+	// Create feature branch at current HEAD (implement commits are already here).
+	branchName := fmt.Sprintf("evolution/day-%s", day)
+	e.branchName = branchName
+
+	// Delete any stale branch with the same name.
+	_ = e.deleteBranch(ctx, branchName)
+
+	if out, err := e.runTool(ctx, "bash", map[string]string{
+		"cmd": fmt.Sprintf("git checkout -b %s", branchName),
+	}); err != nil {
+		return fmt.Errorf("failed to create feature branch %s: %w (output: %s)", branchName, err, out)
+	}
+	e.logger.Info("created feature branch", "branch", branchName)
+
+	// Push with lease; fall back to a plain push on failure.
+	if out, err := e.runTool(ctx, "bash", map[string]string{
+		"cmd": fmt.Sprintf("git push -u origin %q --force-with-lease", branchName),
+	}); err != nil {
+		e.logger.Warn("push with lease failed, retrying", "err", err, "output", out)
+		if out2, err2 := e.runTool(ctx, "bash", map[string]string{
+			"cmd": fmt.Sprintf("git push -u origin %q", branchName),
+		}); err2 != nil {
+			return fmt.Errorf("failed to push branch: %w (output: %s)", err2, out2)
+		}
+	}
+	e.logger.Info("pushed branch", "branch", branchName)
+
+	// Build PR title/body from the session plan.
+	planBytes, _ := os.ReadFile(filepath.Join(e.repoPath, "SESSION_PLAN.md"))
+	plan := string(planBytes)
+	issueNums := extractIssueNumbers(plan)
+
+	sessionTitle := extractSessionTitle(plan)
+	prTitle := fmt.Sprintf("iterate: Day %s evolution session", day)
+	if sessionTitle != "" {
+		prTitle = sessionTitle
+	}
+	prBody := buildPRBody(plan, "")
+
+	prNum, prURL, err := e.createPR(ctx, prTitle, prBody, issueNums)
+	if err != nil {
+		return fmt.Errorf("PR creation failed: %w", err)
+	}
+	e.logger.Info("PR created", "number", prNum, "url", prURL)
+
+	return e.savePRState()
+}
+
+// RunReviewPhase runs an AI self-review of the open PR.
+func (e *Engine) RunReviewPhase(ctx context.Context, p iteragent.Provider) error {
+	ctx, cancel := withTimeout(ctx)
+	defer cancel()
+
+	if e.prNumber == 0 {
+		e.logger.Info("no PR to review — skipping review phase")
+		return nil
+	}
+
+	identity, err := os.ReadFile(filepath.Join(e.repoPath, "docs/IDENTITY.md"))
+	if err != nil {
+		e.logger.Warn("failed to load IDENTITY.md for review phase", "err", err)
+	}
+	systemPrompt := buildSystemPrompt(e.repoPath, string(identity))
+
+	if err := e.reviewPR(ctx, p, e.tools, systemPrompt, e.skills); err != nil {
+		e.logger.Warn("PR review encountered issues", "err", err)
+	}
+	return nil
+}
+
+// RunMergePhase merges the open PR, clears state, and returns to main.
+func (e *Engine) RunMergePhase(ctx context.Context) error {
+	ctx, cancel := withTimeout(ctx)
+	defer cancel()
+
+	if e.prNumber == 0 {
+		e.logger.Info("no PR to merge — skipping merge phase")
+		return nil
+	}
+
+	if err := e.mergePR(ctx); err != nil {
+		return fmt.Errorf("merge failed: %w", err)
+	}
+	e.logger.Info("PR merged", "number", e.prNumber)
+
+	e.clearPRState()
+
+	if err := e.switchToMain(ctx); err != nil {
+		e.logger.Warn("failed to switch to main after merge", "err", err)
+	}
+
+	// Pull to make sure local main is up-to-date.
+	if out, err := e.runTool(ctx, "bash", map[string]string{
+		"cmd": "git pull origin main",
+	}); err != nil {
+		e.logger.Warn("pull after merge failed", "err", err, "output", out)
+	}
+
+	return nil
+}