fix(jetbrains): recover interrupted backend startup

[marius-kilocode]

JetBrains backend startup can be interrupted in two ways that previously left user-visible state stale or stuck.

When the startup event stream stalls, the connection layer delegates a full reconnect. The app layer now allows that delegated reconnect while the app is still in Connecting, so startup can recover instead of staying in Connecting until tests or UI waits time out.

When restart or reinstall interrupts in-flight startup REST loading, canceled HTTP calls can still unwind with stale connection failures. The app now respects coroutine cancellation before converting startup load exceptions into app errors, so canceled loads cannot overwrite the restarted backend state.

The app-service tests use one shared startup wait helper with diagnostics instead of scattered short waits, include regression coverage for startup SSE timeout recovery, and the JetBrains agent guidance now documents deterministic integration-test synchronization with centralized timeout watchdogs only when unavoidable.

[kilo-code-bot]

Code Review Summary

Status: 1 Issues Found | Recommendation: Address before merge

Overview

Severity	Count
CRITICAL	0
WARNING	1
SUGGESTION	0

Issue Details (click to expand)

WARNING

File	Line	Issue
packages/kilo-jetbrains/backend/src/main/kotlin/ai/kilocode/backend/app/KiloBackendAppService.kt	281	Removing the Connecting guard lets a stale queued reconnect restart a newer startup attempt.

Fix these issues in Kilo Cloud

Files Reviewed (3 files)

• .changeset/jetbrains-restart-loading.md - 0 issues
• packages/kilo-jetbrains/backend/src/main/kotlin/ai/kilocode/backend/app/KiloBackendAppService.kt - 1 issue
• packages/kilo-jetbrains/backend/src/test/kotlin/ai/kilocode/backend/app/KiloBackendAppServiceTest.kt - 0 issues

Previous Review Summaries (2 snapshots, latest commit 971a418)

Current summary above is authoritative. Previous snapshots are kept for context only.

Previous review (commit 971a418)

Status: No Issues Found | Recommendation: Merge

Files Reviewed (3 files)

• .changeset/jetbrains-restart-loading.md
• packages/kilo-jetbrains/AGENTS.md
• packages/kilo-jetbrains/backend/src/main/kotlin/ai/kilocode/backend/app/KiloBackendAppService.kt

Previous review (commit 90dce3c)

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 files)

• packages/kilo-jetbrains/backend/src/test/kotlin/ai/kilocode/backend/app/KiloBackendAppServiceTest.kt

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_{Review guidance: REVIEW.md from base branch main}