fix: Reconcile orphaned changesets when phases are manually deleted

Manually deleting phases left their parent changeset as "applied",
causing the Plan tab to show a stale "Created N phases" banner with
no phases visible.

- deletePhase now checks if all phases from a changeset are gone and
  marks it reverted
- PlanSection filters out dismissed agents so dismissed banners stay
  hidden
- revertChangeSet marks reverted before entity deletion to prevent
  ghost state on partial failure
- deletePhase invalidation now includes listChangeSets

apps/web/src/components/execution/PlanSection.tsx

@@ -27,6 +27,7 @@ export function PlanSection({
         (a) =>
           a.mode === "plan" &&
           a.initiativeId === initiativeId &&
+          !a.userDismissedAt &&
           ["running", "waiting_for_input", "idle"].includes(a.status),
       )
       .sort(

apps/web/src/lib/invalidation.ts

@@ -52,7 +52,7 @@ const INVALIDATION_MAP: Partial<Record<MutationName, QueryName[]>> = {
 
   // --- Phases ---
   createPhase: ["listPhases", "listInitiativePhaseDependencies"],
-  deletePhase: ["listPhases", "listInitiativeTasks", "listInitiativePhaseDependencies"],
+  deletePhase: ["listPhases", "listInitiativeTasks", "listInitiativePhaseDependencies", "listChangeSets"],
   updatePhase: ["listPhases", "getPhase"],
   approvePhase: ["listPhases", "listInitiativeTasks"],
   queuePhase: ["listPhases"],