Wire Marvin tasks adapter into the daemon

main constructs the Marvin adapter (command overridable via
ANTIDRIFT_MARVIN_CMD) and injects it. Adds a web test asserting the
planning state payload carries today's tasks.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

cmd/antidriftd/main.go

@@ -15,6 +15,7 @@ import (
 	"antidrift/internal/session"
 	"antidrift/internal/statusfile"
 	"antidrift/internal/store"
+	"antidrift/internal/tasks"
 	"antidrift/internal/web"
 )
 
@@ -46,6 +47,13 @@ func main() {
 		log.Printf("ai: %s backend (coach + drift judge + nudge)", backend.Name())
 	}
 
+	// Wire the Tasks port: Amazing Marvin via ampy's `am` CLI. The command is
+	// overridable with ANTIDRIFT_MARVIN_CMD (e.g. "uv run am" or an absolute
+	// path). A missing or failing CLI degrades to no tasks panel at fetch time —
+	// planning still works.
+	ctrl.SetTasks(tasks.NewMarvin(os.Getenv("ANTIDRIFT_MARVIN_CMD")))
+	log.Printf("tasks: marvin adapter (am)")
+
 	// Mirror runtime status to ~/.antidrift_status for a window-manager bar.
 	// A misconfigured home dir degrades to no status file, not a failed start.
 	if statusPath, err := statusfile.DefaultPath(); err != nil {