wealthfolio: bump memory 64Mi → 1Gi (limit) / 256Mi (request)

## Context

Pod was OOMKilled after today's broker-sync Phase 3 import grew the
activity DB from ~10 rows (Phase 0 demo) to ~700 (Fidelity + cash-flow
matches across 6 accounts). `/api/v1/net-worth` and
`/valuations/history` materialise the full history in memory to render
the dashboard chart.

`kubectl describe pod` showed Back-off restarting failed container;
`kubectl top pod` reported 14Mi steady-state but spikes crossed the
64Mi cap.

## This change

Bump container resources to:
- requests.memory: 64Mi → 256Mi
- limits.memory:  64Mi → 1Gi

CPU unchanged. 1Gi is generous for the current 700-activity DB +
chart rendering, with headroom for another year of growth before we
need to revisit (VPA will flag if actual use exceeds upperBound).

## Verification

### Automated
`scripts/tg apply stacks/wealthfolio` → Apply complete! Resources: 0
added, 4 changed, 0 destroyed.

### Manual
$ kubectl -n wealthfolio get pod -l app=wealthfolio -o jsonpath='{.items[0].spec.containers[0].resources}'
→ {"limits":{"memory":"1Gi"},"requests":{"cpu":"10m","memory":"256Mi"}}

$ kubectl -n wealthfolio get pods -l app=wealthfolio
NAME                           READY   STATUS    RESTARTS   AGE
wealthfolio-86c8696b9c-nzwkf   1/1     Running   0          51s

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

stacks/wealthfolio/main.tf

@@ -149,13 +149,18 @@ resource "kubernetes_deployment" "wealthfolio" {
             name       = "data"
             mount_path = "/data"
           }
+          # 2026-04-18 OOM after broker-sync Phase 3 landed (~700 activities
+          # across 6 accounts including Fidelity + matched cash flows). The
+          # /api/v1/net-worth + /valuations/history endpoints materialise the
+          # full history in memory for the chart; 64Mi was a Phase-0 guess
+          # that fit a 10-activity demo DB and nothing bigger.
           resources {
             requests = {
               cpu    = "10m"
-              memory = "64Mi"
+              memory = "256Mi"
             }
             limits = {
-              memory = "64Mi"
+              memory = "1Gi"
             }
           }
         }