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/server/trpc/routers/phase.ts

@@ -6,7 +6,7 @@ import { TRPCError } from '@trpc/server';
 import { z } from 'zod';
 import type { Phase } from '../../db/schema.js';
 import type { ProcedureBuilder } from '../trpc.js';
-import { requirePhaseRepository, requireTaskRepository, requireBranchManager, requireInitiativeRepository, requireProjectRepository, requireExecutionOrchestrator, requireReviewCommentRepository } from './_helpers.js';
+import { requirePhaseRepository, requireTaskRepository, requireBranchManager, requireInitiativeRepository, requireProjectRepository, requireExecutionOrchestrator, requireReviewCommentRepository, requireChangeSetRepository } from './_helpers.js';
 import { phaseBranchName } from '../../git/branch-naming.js';
 import { ensureProjectClone } from '../../git/project-clones.js';
 
@@ -98,6 +98,29 @@ export function phaseProcedures(publicProcedure: ProcedureBuilder) {
       .mutation(async ({ ctx, input }) => {
         const repo = requirePhaseRepository(ctx);
         await repo.delete(input.id);
+
+        // Reconcile any applied changesets that created this phase.
+        // If all created phases in a changeset are now deleted, mark it reverted.
+        if (ctx.changeSetRepository) {
+          try {
+            const csRepo = requireChangeSetRepository(ctx);
+            const affectedChangeSets = await csRepo.findAppliedByCreatedEntity('phase', input.id);
+            for (const cs of affectedChangeSets) {
+              const createdPhaseIds = cs.entries
+                .filter(e => e.entityType === 'phase' && e.action === 'create')
+                .map(e => e.entityId);
+              const survivingPhases = await Promise.all(
+                createdPhaseIds.map(id => repo.findById(id)),
+              );
+              if (survivingPhases.every(p => p === null)) {
+                await csRepo.markReverted(cs.id);
+              }
+            }
+          } catch {
+            // Best-effort reconciliation — don't fail the delete
+          }
+        }
+
         return { success: true };
       }),