Nebula: Recent Activity improvements in sidebar (#7055)

<!--

## title your PR with this format: "[SDK/Dashboard/Portal] Feature/Fix: Concise title for the changes"

If you did not copy the branch name from Linear, paste the issue tag here (format is TEAM-0000):

## Notes for the reviewer

Anything important to call out? Be sure to also clarify these in your comments.

## How to test

Unit tests, playground, etc.

-->

<!-- start pr-codex -->

---

## PR-Codex overview
This PR focuses on enhancing the `TransactionsSection` component in the dashboard by modifying the transaction fetch limit and adding a filter for recent transactions.

### Detailed summary
- Updated `className` of `ChainIconClient` to include `rounded-full border`.
- Increased transaction limit from `10` to `20` in the URL query parameters.
- Added a filter for transactions from the last three months using `filter_block_timestamp_gte`.
- Changed the type of `json.data` from `WalletTransaction[]` to `WalletTransaction[]?`, allowing for undefined.
- Implemented a fallback to return an empty array if `json.data` is undefined.

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your question}`

<!-- end pr-codex -->

Author: MananTank

apps/dashboard/src/app/nebula-app/(app)/components/TransactionsSection/TransactionsSection.tsx

@@ -88,7 +88,7 @@ function TransactionInfo(props: {
     <div className="relative flex h-[48px] items-center gap-2.5 rounded-lg px-2 py-1 hover:bg-accent">
       <ChainIconClient
         client={props.client}
-        className="size-8"
+        className="size-8 rounded-full border"
         src={chainMeta?.icon?.url || ""}
       />
 
@@ -167,20 +167,29 @@ export function TransactionsSection(props: {
       const url = new URL(
         `https://insight.${isProd ? "thirdweb" : "thirdweb-dev"}.com/v1/wallets/${account.address}/transactions`,
       );
-      url.searchParams.set("limit", "10");
+      url.searchParams.set("limit", "20");
       url.searchParams.set("decode", "true");
       url.searchParams.set("clientId", nebulaAppThirdwebClient.clientId);
 
+      const threeMonthsAgoUnixTime = Math.floor(
+        (Date.now() - 3 * 30 * 24 * 60 * 60 * 1000) / 1000,
+      );
+
+      url.searchParams.set(
+        "filter_block_timestamp_gte",
+        `${threeMonthsAgoUnixTime}`,
+      );
+
       for (const chain of chains) {
         url.searchParams.append("chain", chain.toString());
       }
 
       const response = await fetch(url.toString());
       const json = (await response.json()) as {
-        data: WalletTransaction[];
+        data?: WalletTransaction[];
       };
 
-      return json.data;
+      return json.data ?? [];
     },
     retry: false,
     enabled: !!account && !!activeChain,