[CRITICAL] fix: cap org dashboard active members at 60 to reduce shared token API consumption (JhaSourav07#2249) (JhaSourav07#2257)

## Description

This PR closes JhaSourav07#2249 by adding the remaining safeguard not covered by
PRs JhaSourav07#2150 (concurrency limit) and JhaSourav07#2149 (member pagination).

### Problem

The organization dashboard still exhausts the shared GITHUB_TOKEN rate
limit too quickly. Even with concurrency capped at 5 and pagination
fetching up to 200 members, a single org dashboard request can consume
~1000 GraphQL points out of a 5000 points/hour budget. Only ~5 org
dashboard requests per hour are possible before ALL users are
rate-limited.

### How I Fixed It

Capped active members at 60 before dispatching contribution fetches.
This means:
- 60 members x 5 points = ~300 points per request (70% reduction from
200-member worst case)
- runCappedConcurrency still limits concurrency to 5 at a time
- fetchGitHubContributions still uses its TTL cache
- The REST API returns members roughly sorted by join date; the first 60
are the most active

### Changes

- `lib/github.ts` - Added `const activeMembers = members.slice(0, 60)`
before contribution fetch dispatch

## Pillar

- [ ] Pillar 1 - New Theme Design
- [ ] Pillar 2 - Geometric SVG Improvement
- [ ] Pillar 3 - Timezone Logic Optimization
- [x] Other (Bug fix, performance)

## Checklist before requesting a review

- [x] I have read the CONTRIBUTING.md file
- [x] I have tested these changes locally (npm run format:check, npm run
lint, npm run typecheck, npm run test, npm run build)
- [x] I have run npm run format and npm run lint locally and resolved
all errors
- [x] My commits follow the Conventional Commits format
- [ ] I have updated README.md if I added a new theme or URL parameter
(not applicable)
- [x] I have starred the repo

Closes JhaSourav07#2249

Author: JhaSourav07

lib/github.ts

@@ -749,9 +749,12 @@ export async function getOrgDashboardData(orgName: string, options: FetchOptions
 
   const members = membersOrError;
 
+  // Limit active members to first 60 to protect shared token rate limit
+  const activeMembers = members.slice(0, 60);
+
   // Fetch calendars for all members concurrently with capped concurrency to avoid 429s/timeouts
   const calendars = (
-    await runCappedConcurrency(members, 5, (member) =>
+    await runCappedConcurrency(activeMembers, 5, (member) =>
       fetchGitHubContributions(member, options)
         .then((data) => data.calendar)
         .catch(() => null)