fix: Slow Unity responses now bring the Editor forward

[hatayama]

Summary

• Unity is brought to the foreground when a connected Editor becomes slow, stalled, or times out unexpectedly.
• Windows focus restore now returns to the previous window reliably without resizing maximized windows.

User Impact

• Before, automatic focus recovery only ran for connection failures before dispatch, so accepted but stalled Unity requests could remain hidden in the background.
• After this change, abnormal slow-response paths try to surface the Editor, recoverable retries restore the original window, and terminal timeout failures leave Unity visible so the user can see what needs attention.

Changes

• Classify slow-response focus triggers for pre-accept timeouts, heartbeat-reported main-thread stalls, heartbeat silence, and abnormal final-response timeouts.
• Report main-thread stalls from IPC heartbeats and include focus reasons in recovery logs.
• Update Windows focus restore to use thread input attachment while preserving maximized foreground windows.

Verification

• From cli/: go test ./internal/cli ./internal/unityipc -run 'Focus|ConnectionRetry|Heartbeat|Compile' -count=1
• From repo root: ./scripts/check-go-cli.sh
• Codex review against v3-beta with check-go-cli.sh: clean, no accepted/actionable findings.
• Manual Windows focus probes confirmed minimized Unity is restored/focused and foreground focus can return to the original window.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 28623905-2508-4342-af3c-475b0ddafb95

📥 Commits

Reviewing files that changed from the base of the PR and between e89cfc5 and 16e1a4e.

📒 Files selected for processing (2)

• cli/internal/cli/connection_retry.go
• cli/internal/cli/connection_retry_test.go

📝 Walkthrough

Walkthrough

Introduces a connectionRetryFocusController with a typed connectionRetryFocusReason enum to centralize Unity focus state, deferred restoration, and error classification during connection retries. Adds a WithMainThreadStallHandler callback to the IPC client to route stall events into the controller. Rewrites the Windows foreground-window restore script to use thread-attach/minimize-aware Win32 operations.

Changes

Connection Retry Focus Controller, IPC Stall Handler, and Windows Restore

Layer / File(s)	Summary
IPC client mainThreadStallHandler hook cli/internal/unityipc/client.go, cli/internal/unityipc/client_heartbeat_test.go	Adds mainThreadStallHandler func(float64) field to Client, the WithMainThreadStallHandler fluent setter, and invocation of the callback at the heartbeat stall threshold alongside the existing progress message; test asserts handler fires once with the expected stall duration.
Focus reason enum and connectionRetryFocusController cli/internal/cli/connection_retry.go	Defines connectionRetryFocusReason constants and the connectionRetryFocusController struct with methods for construction, deferred restoration, one-shot focus guarding, tryFocus/tryFocusProcess, and stall-triggered focusing; adds connectionRetryFocusReasonForError classification; updates three Vibe log helpers to include the reason field.
Retry loop wiring cli/internal/cli/connection_retry.go	Updates sendWithTransientConnectionRetry to instantiate the controller up-front, defer focus restoration, attach the IPC stall handler to the controller, route errors through connectionRetryFocusReasonForError, and replace inline focus logic with controller calls.
Focus reason and retry integration tests cli/internal/cli/connection_retry_test.go	Unit tests for connectionRetryFocusReasonForError across all timeout and exclusion cases; updated Vibe log assertions adding the reason field; TCP-injection integration test asserting focus-without-restore on pre-accept timeout.
Windows restore script: thread-aware Win32 interop cli/internal/cli/focus.go, cli/internal/cli/focus_test.go	Adds includeThreadFocus parameter to buildWindowsFocusInteropTypeDefinition with conditional P/Invoke declarations; rewrites buildRestoreWindowsForegroundWindowScript to attach thread input, handle minimized windows, and detach in a finally block; updates callers and adds/updates tests for the new PowerShell substrings.

Sequence Diagram(s)

sequenceDiagram
  participant RetryLoop as sendWithTransientConnectionRetry
  participant Controller as connectionRetryFocusController
  participant IPCClient as unityipc.Client
  participant FocusScript as focusUnityProcess

  RetryLoop->>Controller: newConnectionRetryFocusController(...)
  RetryLoop->>IPCClient: WithMainThreadStallHandler(controller.onMainThreadStall)
  IPCClient-->>Controller: onMainThreadStall(stallSeconds) [on threshold]
  Controller->>FocusScript: tryFocus(main_thread_stall, ...)
  RetryLoop->>RetryLoop: error occurs → connectionRetryFocusReasonForError
  RetryLoop->>Controller: tryFocus(reason, ...) + keepUnityFocusedAfterReturn
  RetryLoop->>Controller: doRestoreFocus [deferred on return]

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Estimated code review effort

🎯 4 (Complex) | ⏱️ ~60 minutes

Possibly related PRs

• hatayama/unity-cli-loop#1199: Modifies the same connection retry and focus-with-restore paths in connection_retry.go and focus.go, directly overlapping with the controller and focus logic introduced here.
• hatayama/unity-cli-loop#1215: Adds structured Vibe logging to the same focus helpers in connection_retry.go and focus.go that this PR extends with the reason field.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 56.25% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title directly and concisely summarizes the main change: enabling automatic focus recovery when Unity Editor responses are slow, which is the core objective of this PR.
Description check	✅ Passed	The description is detailed and clearly related to the changeset, explaining the user impact, specific changes made, and verification steps performed.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/auto-front-window

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@cli/internal/cli/connection_retry.go`:
- Around line 107-109: The issue is that in the tryFocus function at lines
107-109, setting controller.attempted = true when process discovery fails or
returns nil permanently marks the focus attempt as complete, preventing the
terminal-timeout path at lines 232-235 from retrying focus recovery on the same
reused controller. When process discovery fails transiently, this overly
aggressive flag prevents the final recovery attempt from succeeding. Fix this by
not setting controller.attempted = true in the error case where runningProcess
discovery fails or returns nil, allowing the later terminal-timeout path to
still attempt focus recovery if needed.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: bd1cd2af-f595-4c8b-8f9c-b673b3a2b3d3

📥 Commits

Reviewing files that changed from the base of the PR and between 2ee34eb and e89cfc5.

📒 Files selected for processing (6)

• cli/internal/cli/connection_retry.go
• cli/internal/cli/connection_retry_test.go
• cli/internal/cli/focus.go
• cli/internal/cli/focus_test.go
• cli/internal/unityipc/client.go
• cli/internal/unityipc/client_heartbeat_test.go

[cubic-dev-ai]

2 issues found across 6 files

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