Move impl to cpp, fix lifetime issues.

Took 11 minutes

Took 2 minutes

cockatrice/src/interface/intents/intent.cpp

@@ -1 +1,32 @@
 #include "intent.h"
+
+Intent::Intent(QObject *parent) : QObject(parent)
+{
+    // An intent is done as soon as it reports success or failure. Deleting it
+    // also tears down its dependency chain and disconnects any signal wiring.
+    connect(this, &Intent::finished, this, &QObject::deleteLater);
+    connect(this, &Intent::failed, this, &QObject::deleteLater);
+}
+
+Intent::~Intent() = default;
+
+void Intent::execute()
+{
+    if (checkPrecondition()) {
+        onPreconditionSatisfied();
+    } else {
+        onPreconditionNotSatisfied();
+    }
+}
+
+void Intent::runDependency(Intent *dependency)
+{
+    dependency->setParent(this);
+    connect(dependency, &Intent::finished, this, [this]() {
+        // Re-check after dependency finishes
+        this->execute();
+    });
+    connect(dependency, &Intent::failed, this, &Intent::failed);
+
+    dependency->execute();
+}