waitForTaskIdle used time.NewTicker(5s) which delays the first poll
by 5 seconds. Debugger tracing proved the failure mechanism: on slow
CI (Windows), the first poll at 5s sees "working" (idle patch has not
landed due to goroutine scheduling), needs poll #2 at 10s, but the
25s context expires before it fires.
Two changes:
1. Use r.clock.NewTicker (quartz) with time.Nanosecond initial
interval and Reset(5s) for immediate first poll. Tests inject a
mock clock via clitest.NewWithClock for deterministic control.
2. Rewrite WaitsForWorkingAppState test with quartz traps
(NewTicker + TickerReset) for deterministic synchronization
instead of racing goroutines. Fix PausedDuringWaitForReady
sync point.
Closes DEVEX-381
## Overview
This change promotes the tasks CLI commands from `coder exp task` to
`coder task`, marking them as generally available (GA).
## Migration
Users will need to update their scripts from:
```shell
coder exp task create "my task"
```
To:
```shell
coder task create "my task"
```
---
🤖 This change was written by Claude Sonnet 4.5 Thinking using [mux](https://github.com/coder/mux) and reviewed by a human 🏄🏻♂️
Mathias Fredriksson