[docs] update docs for 0.9.87

Make a few updates to the docs for 0.9.87, and change "major" to "substantive"
in signal docs to indicate the last revision to the semantics.

site/src/docs/design/architecture/runner-loop.md

@@ -198,4 +198,4 @@ sustainably high-quality over time.
 runner is to handle all of the ways tests can fail, just like the primary job of
 a compiler is to handle all the ways users can write incorrect code.
 
-_Last major revision: 2024-12-06_
+_Last substantive revision: 2024-12-06_

site/src/docs/design/architecture/signal-handling.md

@@ -228,7 +228,12 @@ When a test times out, nextest calls `TerminateJobObject` on the job object
 associated with the test immediately. In the future, it would be interesting
 to send a Ctrl-C (or maybe a `WM_CLOSE`?) to the test process first.
 
+When nextest receives a Ctrl-C, it assumes that child tests will also receive
+the same Ctrl-C and terminate themselves. If tests don't exit within the grace
+period (by default, 10 seconds), nextest will terminate them via their
+corresponding job object.
+
 [job objects]: https://learn.microsoft.com/en-us/windows/win32/procthread/job-objects
 [terminate-job-object]: https://docs.microsoft.com/en-us/windows/win32/api/jobapi2/nf-jobapi2-terminatejobobject
 
-_Last major revision: 2024-12-06_
+_Last substantive revision: 2024-12-17_

site/src/docs/features/slow-tests.md

@@ -80,11 +80,20 @@ To send SIGKILL to a process immediately, without a grace period, set `slow-time
 slow-timeout = { period = "60s", terminate-after = 5, grace-period = "0s" }
 ```
 
-<!-- md:version 0.9.61 --> The `slow-timeout.grace-period` setting is also applied to terminations due to Ctrl-C or other signals. With older versions, nextest always waits 10 seconds before sending SIGKILL.
+<!-- md:version 0.9.61 --> For terminations due to Ctrl-C or other signals, the
+`slow-timeout.grace-period` setting is applied. With older versions, nextest
+always waits 10 seconds before sending SIGKILL.
 
 #### Termination on Windows
 
-On Windows, nextest terminates the test immediately in a manner akin to SIGKILL. (On Windows, nextest uses [job objects] to kill the test process and all its descendants.) The `slow-timeout.grace-period` configuration setting is ignored.
+On Windows, nextest terminates the test immediately in a manner akin to SIGKILL.
+(Nextest uses Windows [job objects] to kill the test process and all its
+descendants.) For termination due to timeouts, the `slow-timeout.grace-period`
+configuration setting is ignored.
+
+<!-- md:version 0.9.87 --> For terminations due to Ctrl-C, the
+`slow-timeout.grace-period` setting is applied. With older versions, nextest
+waits indefinitely for the test to shut down.
 
 [process group]: https://en.wikipedia.org/wiki/Process_group
 [job objects]: https://docs.microsoft.com/en-us/windows/win32/procthread/job-objects