perf(desktop): warm common route chunks while idle

[helix4u]

What does this PR do?

Warms the JavaScript chunks for five common Desktop routes after the gateway is open and the foreground has had time to settle. This removes the first-click chunk load/parse pause from Messaging, Artifacts, Cron, Settings, and Capabilities without moving those routes or their data fetches onto the startup critical path.

The warmup is deliberately bounded: it starts after a 1.5 second delay, uses requestIdleCallback when available, imports one chunk at a time with a 350 ms gap after completion, cancels if the gateway closes, and continues after an individual import failure. It runs only in the connected primary window; HUD, browser, and other auxiliary windows do not own normal navigation and do not pay this CPU or memory cost.

It warms code only. Each route still performs its authoritative data load when opened. Agents, Command Center, Profiles, Webhooks, and Starmap remain cold so Desktop does not eagerly parse every optional surface.

Related Issue

N/A

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 🔒 Security fix
• 📝 Documentation update
• ✅ Tests (adding or improving test coverage)
• ♻️ Refactor (no behavior change)
• 🎯 New skill (bundled or hub)

Changes Made

• Add a cancellable idle warmup scheduler for dynamic imports.
• Serialize route imports by completion rather than merely staggering their start times.
• Continue the queue after an individual chunk fails.
• Share loader functions between React lazy routes and the warmup queue so each module uses the same cached dynamic import.
• Warm Messaging, Artifacts, Cron, Settings, and Capabilities from one owner after gateway readiness.
• Limit warmup to the connected primary window so HUD, browser, and auxiliary windows do not load routes they cannot navigate to.

How to Test

1. Run npm --workspace apps/desktop exec vitest run src/lib/idle-warmup.test.ts src/app/contrib/route-loaders.test.ts.
2. Run npm --workspace apps/desktop run typecheck.
3. Run affected-file ESLint for the scheduler, route loaders, wiring, surfaces, and tests.

Focused result: 4 Vitest tests passed. Desktop renderer, Electron, and E2E typechecks passed. Affected-file ESLint and git diff --check passed.

Desktop performance series

This change is one independently reviewable layer of the same Desktop startup and first-interaction performance pass.

• perf(cli): dispatch serve without the full parser tree #96749 removes unrelated CLI parser work from the hermes serve entry path.
• perf(serve): overlap cached startup preparation #96750 overlaps independent cached startup preparation before the existing readiness join.
• perf(serve): move Desktop runtime services after bind #96751 lets the verified local Desktop control socket bind before nonessential runtime services finish loading.
• perf(desktop): start the backend before first-window setup #97032 starts the backend before first-window setup and defers noncritical Electron integrations.
• perf(desktop): make the shell interactive before startup hydration #97027 releases the renderer boot barrier once the gateway socket and active profile are ready, while noncritical hydration continues.
• perf(desktop): paint cached shell state before live refresh #96717 paints connection/profile-scoped session and project navigation from bounded snapshots while live refresh continues.
• perf(desktop): keep cached transcript visible while session resumes #96721 paints the exact connection/profile-scoped remembered transcript before backend/profile hydration, then keeps it visible while the live runtime resumes.
• fix(desktop): retain the largest cacheable transcript tail #96921 prevents the existing transcript cache from discarding a complete suffix that still fits its storage bound.
• perf(desktop): warm common route chunks while idle #97037 warms common lazy route code serially during idle time in the connected primary window, without prefetching route data.
• perf(desktop): progressively hydrate Bot Mode roster #96728 progressively hydrates Bot Mode roster presentation without changing canonical chat identity.

The three Python backend PRs share startup files but solve separate stages. Recommended landing order is #96749, then #96750, then #96751, rebasing the next PR only after the preceding one lands. #97032 is an independently reviewable Electron ordering change. The remaining renderer and Bot Mode PRs can also land independently; their effects compose without making cached state authoritative.
This PR owns idle code warmup: the connected primary window warms a small route set after the foreground settles, without prefetching route data.

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: Windows 11

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A

Screenshots / Logs

Not applicable. The focused tests verify serialization, cancellation, and failure continuation.

[Enough1122]

AI code review — automated review for reference; please use your judgment.

perf(desktop): warm common route chunks while idle — idle-priority chunk preloading to remove first-click parse pause.

• apps/desktop/src/lib/idle-warmup.ts:212 scheduleIdleWarmup — serializes dynamic imports via requestIdleCallback + gapMs:350 after initialDelayMs:1500. Each loader awaited before next scheduled, errors swallowed (catch(()=>undefined)) so one missing chunk doesn't block rest. Cancel unregisters both timeout and idle handles. Keeps parsing serialized so BG cannot compete with chat.
• apps/desktop/src/app/contrib/route-loaders.ts:18 COMMON_ROUTE_WARMUP_LOADERS — only Messaging/Artifacts/Cron/Settings/Skills (light→heavy, frequent-first). Intentionally not preloading Agents/CommandCenter/Profiles/Webhooks/Starmap which are rarer/heavier.
• apps/desktop/src/app/contrib/wiring.tsx:106 gated by shouldWarmCommonRoutes(gatewayOpen, auxiliaryWindow) — secondary HUD/browser windows don't warm, and disconnected primary doesn't either. Correct guard.
• apps/desktop/src/lib/idle-warmup.test.ts:13 tests: serial wait, continue-after-failure, cancel-before-start.

Approve.

[Enough1122]

AI code review — automated review for reference; please use your judgment.

perf(desktop): warm common route chunks while idle — idle-priority chunk preloading to remove first-click parse pause.

• apps/desktop/src/lib/idle-warmup.ts:212 scheduleIdleWarmup — serializes dynamic imports via requestIdleCallback + gapMs:350 after initialDelayMs:1500. Each loader awaited before next scheduled, errors swallowed (catch(()=>undefined)) so one missing chunk doesn't block rest. Cancel unregisters both timeout and idle handles. Keeps parsing serialized so BG cannot compete with chat.
• apps/desktop/src/app/contrib/route-loaders.ts:18 COMMON_ROUTE_WARMUP_LOADERS — only Messaging/Artifacts/Cron/Settings/Skills (light→heavy, frequent-first). Intentionally not preloading Agents/CommandCenter/Profiles/Webhooks/Starmap which are rarer/heavier.
• apps/desktop/src/app/contrib/wiring.tsx:106 gated by shouldWarmCommonRoutes(gatewayOpen, auxiliaryWindow) — secondary HUD/browser windows don't warm, and disconnected primary doesn't either. Correct guard.
• apps/desktop/src/lib/idle-warmup.test.ts:13 tests: serial wait, continue-after-failure, cancel-before-start.

Approve.

[helix4u]

[helix4u]

Closing because this was part of the older Desktop performance series and its route-wiring target has since been decomposed. The related series was measured and reduced to the portions with demonstrated gains, while this branch has no current-main product measurement that justifies rebuilding it. Any future route warming should start from current main with fresh timings.