Feat: Implement Missing request timeout handling in frontend API calls

[Lansa-18]

Closes #122

Feat: Request Timeout Handling for Frontend API Calls (#122)

Summary

Adds request timeout handling to all frontend API calls. Previously, apiClient (openapi-fetch) delegated to native fetch with no timeout, meaning any network request would hang indefinitely if the backend was unresponsive — degrading UX especially in poor connectivity environments.

The fix wraps fetchClient with an AbortController-based timeout at the api-client.ts level, so every existing and future API call inherits the 30s default automatically with no per-call changes needed. withRetry is also patched to not retry timed-out requests (which would have silently extended the hang by ~7s). Timeout errors surface a user-readable message instead of a silent hang.

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Testing

Unit Tests — New Utility

cd app/frontend
pnpm test -- --testPathPatterns=fetch-timeout --no-coverage
# Tests: 12 passed, 12 total

Covers:

• Request resolves normally before timeout
• Timeout fires and aborts the request
• Timer is cleared on successful response (no dangling timers)
• Pre-aborted caller signal causes immediate abort
• Caller signal fires independently before timeout
• Default DEFAULT_TIMEOUT_MS (30s) is used when no value is specified
• isTimeoutError correctly identifies AbortError and TimeoutError, rejects plain errors

Full Test Suite — Regression Check

pnpm test -- --no-coverage
# Test Suites: 10 passed, 10 total
# Tests:       94 passed, 94 total

Type Check

pnpm type-check
# clean, no output

Build

pnpm build
# ✓ Compiled successfully in 700ms

Lint

pnpm lint
# 14 pre-existing errors, none in files touched by this PR
# All errors are in unrelated components (campaigns/page.tsx, DashboardContent.tsx, useActivity.ts, etc.)

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Notes

No UI changes. Timeout errors surface through existing error states in TanStack Query consumers.

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Checklist

• Tests added or updated for new/changed behavior
• Existing tests pass
• No secrets, keys, or seed phrases committed
• Follows the coding conventions in the relevant service README
• PR is focused on a single concern

[Lansa-18]

@kilodesodiq-arch Kindly review the PR. Thank you.

[kilodesodiq-arch]

@Lansa-18 please check, the CI didnt run.