fix(jetbrains): recover stalled startup event streams

[marius-kilocode]

JetBrains startup currently assumes the SSE event stream either opens or fails through OkHttp. When that callback never arrives, connection state stays Connecting and downstream workspace or session flows can wait until their own timeouts.

This adds a bounded SSE-open timeout that cancels the stalled source and goes through the existing reconnect path. The test fakes now avoid cross-thread mutable list races, and the chat manager malformed-event test waits until its collection subscription is attached before emitting events. That keeps the suite focused on the intended behavior instead of scheduler timing.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 files)

• packages/kilo-jetbrains/backend/src/main/kotlin/ai/kilocode/backend/app/KiloBackendConnectionService.kt

Previous Review Summary (commit 8c37da0)

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

Previous review (commit 8c37da0)

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/KiloBackendConnectionService.kt	122	timeoutJob is introduced but never canceled in dispose(), so plugin shutdown can leave the delayed reconnect timer alive briefly after unload.

Fix these issues in Kilo Cloud

Files Reviewed (4 files)

• .changeset/jetbrains-sse-reconnect-timeout.md - 0 issues
• packages/kilo-jetbrains/backend/src/main/kotlin/ai/kilocode/backend/app/KiloBackendConnectionService.kt - 1 issue
• packages/kilo-jetbrains/backend/src/test/kotlin/ai/kilocode/backend/app/KiloBackendChatManagerTest.kt - 0 issues
• packages/kilo-jetbrains/frontend/src/test/kotlin/ai/kilocode/client/testing/FakeWorkspaceRpcApi.kt - 0 issues

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_{Reviewed by gpt-5.4-20260305 · Input: 49.5K · Output: 4.1K · Cached: 191K}

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