fix(poll): revert context inheritance to prevent deadlock

The v1.0.3 change that made poller contexts inherit from the parent
context caused a deadlock where runners would start but never poll
for tasks.

Reverted to using context.Background() for pollingCtx and jobsCtx.
Graceful shutdown still works via explicit Shutdown() call which
cancels the polling context.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

internal/app/cmd/daemon.go

@@ -218,7 +218,7 @@ func runDaemon(ctx context.Context, daemArgs *daemonArgs, configFile *string) fu
 			}
 		}()
 
-		poller := poll.New(ctx, cfg, cli, runner)
+		poller := poll.New(cfg, cli, runner)
 		poller.SetBandwidthManager(bandwidthManager)
 
 		if daemArgs.Once || reg.Ephemeral {

internal/app/poll/poller.go

@@ -40,11 +40,11 @@ type Poller struct {
 	done chan struct{}
 }
 
-// New creates a new Poller instance with the given context for shutdown propagation.
-func New(ctx context.Context, cfg *config.Config, client client.Client, runner *run.Runner) *Poller {
-	// Inherit from parent context so shutdown signals propagate properly
-	pollingCtx, shutdownPolling := context.WithCancel(ctx)
-	jobsCtx, shutdownJobs := context.WithCancel(ctx)
+// New creates a new Poller instance.
+func New(cfg *config.Config, client client.Client, runner *run.Runner) *Poller {
+	// Use independent contexts - shutdown is handled explicitly via Shutdown()
+	pollingCtx, shutdownPolling := context.WithCancel(context.Background())
+	jobsCtx, shutdownJobs := context.WithCancel(context.Background())
 
 	done := make(chan struct{})