Document intentional error suppressions with comments (gt-zn9m)

All 156 instances of _ = error suppression in non-test code now have
explanatory comments documenting why the error is intentionally ignored.

Categories of intentional suppressions:
- non-fatal: session works without these - tmux environment setup
- non-fatal: theming failure does not affect operation - visual styling
- best-effort cleanup - defer cleanup on failure paths
- best-effort notification - mail/notifications that should not block
- best-effort interrupt - graceful shutdown attempts
- crypto/rand.Read only fails on broken system - random ID generation
- output errors non-actionable - fmt.Fprint to io.Writer

This addresses the silent failure and debugging concerns raised in the
issue by making the intentionality explicit in the code.

Generated with Claude Code https://claude.com/claude-code

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

internal/cmd/swarm.go

@@ -155,7 +155,7 @@ func init() {
 	swarmCreateCmd.Flags().StringSliceVar(&swarmWorkers, "worker", nil, "Polecat names to assign (repeatable)")
 	swarmCreateCmd.Flags().BoolVar(&swarmStart, "start", false, "Start swarm immediately after creation")
 	swarmCreateCmd.Flags().StringVar(&swarmTarget, "target", "main", "Target branch for landing")
-	_ = swarmCreateCmd.MarkFlagRequired("epic")
+	_ = swarmCreateCmd.MarkFlagRequired("epic") // cobra flags: error only at runtime if missing
 
 	// Status flags
 	swarmStatusCmd.Flags().BoolVar(&swarmStatusJSON, "json", false, "Output as JSON")
@@ -300,7 +300,7 @@ func runSwarmCreate(cmd *cobra.Command, args []string) error {
 		}
 	}
 
-	// Get the updated swarm
+	// Get the updated swarm (just created, error would be surprising)
 	sw, _ = mgr.GetSwarm(swarmEpic)
 
 	// Save to store
@@ -640,7 +640,7 @@ func runSwarmLand(cmd *cobra.Command, args []string) error {
 
 	// Create manager and land
 	mgr := swarm.NewManager(foundRig)
-	// Reload swarm into manager
+	// Reload swarm into manager (recreates from store, errors non-fatal)
 	_, _ = mgr.Create(sw.EpicID, sw.Workers, sw.TargetBranch)
 	_ = mgr.UpdateState(sw.ID, sw.State)