refactor(sling): split 1560-line file into 7 focused modules

Extract sling.go into logical components following the established
<cmd>_<feature>.go pattern used elsewhere (crew_helpers.go, etc.):

- sling.go (465 lines): command definition + main runSling()
- sling_helpers.go (370): bead/tmux/agent utilities
- sling_formula.go (270): formula handling + wisp parsing
- sling_dog.go (158): dog dispatch logic
- sling_batch.go (154): batch slinging to rigs
- sling_convoy.go (125): auto-convoy creation
- sling_target.go (86): target resolution functions

No functional changes - pure code organization refactor.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/cmd/sling_batch.go

@@ -0,0 +1,154 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/steveyegge/gastown/internal/beads"
+	"github.com/steveyegge/gastown/internal/events"
+	"github.com/steveyegge/gastown/internal/style"
+)
+
+// runBatchSling handles slinging multiple beads to a rig.
+// Each bead gets its own freshly spawned polecat.
+func runBatchSling(beadIDs []string, rigName string, townBeadsDir string) error {
+	// Validate all beads exist before spawning any polecats
+	for _, beadID := range beadIDs {
+		if err := verifyBeadExists(beadID); err != nil {
+			return fmt.Errorf("bead '%s' not found", beadID)
+		}
+	}
+
+	if slingDryRun {
+		fmt.Printf("%s Batch slinging %d beads to rig '%s':\n", style.Bold.Render("🎯"), len(beadIDs), rigName)
+		for _, beadID := range beadIDs {
+			fmt.Printf("  Would spawn polecat for: %s\n", beadID)
+		}
+		return nil
+	}
+
+	fmt.Printf("%s Batch slinging %d beads to rig '%s'...\n", style.Bold.Render("🎯"), len(beadIDs), rigName)
+
+	// Track results for summary
+	type slingResult struct {
+		beadID  string
+		polecat string
+		success bool
+		errMsg  string
+	}
+	results := make([]slingResult, 0, len(beadIDs))
+
+	// Spawn a polecat for each bead and sling it
+	for i, beadID := range beadIDs {
+		fmt.Printf("\n[%d/%d] Slinging %s...\n", i+1, len(beadIDs), beadID)
+
+		// Check bead status
+		info, err := getBeadInfo(beadID)
+		if err != nil {
+			results = append(results, slingResult{beadID: beadID, success: false, errMsg: err.Error()})
+			fmt.Printf("  %s Could not get bead info: %v\n", style.Dim.Render("✗"), err)
+			continue
+		}
+
+		if info.Status == "pinned" && !slingForce {
+			results = append(results, slingResult{beadID: beadID, success: false, errMsg: "already pinned"})
+			fmt.Printf("  %s Already pinned (use --force to re-sling)\n", style.Dim.Render("✗"))
+			continue
+		}
+
+		// Spawn a fresh polecat
+		spawnOpts := SlingSpawnOptions{
+			Force:    slingForce,
+			Account:  slingAccount,
+			Create:   slingCreate,
+			HookBead: beadID, // Set atomically at spawn time
+			Agent:    slingAgent,
+		}
+		spawnInfo, err := SpawnPolecatForSling(rigName, spawnOpts)
+		if err != nil {
+			results = append(results, slingResult{beadID: beadID, success: false, errMsg: err.Error()})
+			fmt.Printf("  %s Failed to spawn polecat: %v\n", style.Dim.Render("✗"), err)
+			continue
+		}
+
+		targetAgent := spawnInfo.AgentID()
+		hookWorkDir := spawnInfo.ClonePath
+
+		// Auto-convoy: check if issue is already tracked
+		if !slingNoConvoy {
+			existingConvoy := isTrackedByConvoy(beadID)
+			if existingConvoy == "" {
+				convoyID, err := createAutoConvoy(beadID, info.Title)
+				if err != nil {
+					fmt.Printf("  %s Could not create auto-convoy: %v\n", style.Dim.Render("Warning:"), err)
+				} else {
+					fmt.Printf("  %s Created convoy 🚚 %s\n", style.Bold.Render("→"), convoyID)
+				}
+			} else {
+				fmt.Printf("  %s Already tracked by convoy %s\n", style.Dim.Render("○"), existingConvoy)
+			}
+		}
+
+		// Hook the bead. See: https://github.com/steveyegge/gastown/issues/148
+		townRoot := filepath.Dir(townBeadsDir)
+		hookCmd := exec.Command("bd", "--no-daemon", "update", beadID, "--status=hooked", "--assignee="+targetAgent)
+		hookCmd.Dir = beads.ResolveHookDir(townRoot, beadID, hookWorkDir)
+		hookCmd.Stderr = os.Stderr
+		if err := hookCmd.Run(); err != nil {
+			results = append(results, slingResult{beadID: beadID, polecat: spawnInfo.PolecatName, success: false, errMsg: "hook failed"})
+			fmt.Printf("  %s Failed to hook bead: %v\n", style.Dim.Render("✗"), err)
+			continue
+		}
+
+		fmt.Printf("  %s Work attached to %s\n", style.Bold.Render("✓"), spawnInfo.PolecatName)
+
+		// Log sling event
+		actor := detectActor()
+		_ = events.LogFeed(events.TypeSling, actor, events.SlingPayload(beadID, targetAgent))
+
+		// Update agent bead state
+		updateAgentHookBead(targetAgent, beadID, hookWorkDir, townBeadsDir)
+
+		// Store args if provided
+		if slingArgs != "" {
+			if err := storeArgsInBead(beadID, slingArgs); err != nil {
+				fmt.Printf("  %s Could not store args: %v\n", style.Dim.Render("Warning:"), err)
+			}
+		}
+
+		// Nudge the polecat
+		if spawnInfo.Pane != "" {
+			if err := injectStartPrompt(spawnInfo.Pane, beadID, slingSubject, slingArgs); err != nil {
+				fmt.Printf("  %s Could not nudge (agent will discover via gt prime)\n", style.Dim.Render("○"))
+			} else {
+				fmt.Printf("  %s Start prompt sent\n", style.Bold.Render("▶"))
+			}
+		}
+
+		results = append(results, slingResult{beadID: beadID, polecat: spawnInfo.PolecatName, success: true})
+	}
+
+	// Wake witness and refinery once at the end
+	wakeRigAgents(rigName)
+
+	// Print summary
+	successCount := 0
+	for _, r := range results {
+		if r.success {
+			successCount++
+		}
+	}
+
+	fmt.Printf("\n%s Batch sling complete: %d/%d succeeded\n", style.Bold.Render("📊"), successCount, len(beadIDs))
+	if successCount < len(beadIDs) {
+		for _, r := range results {
+			if !r.success {
+				fmt.Printf("  %s %s: %s\n", style.Dim.Render("✗"), r.beadID, r.errMsg)
+			}
+		}
+	}
+
+	return nil
+}