CmdPal: Replace SupersedingAsyncGate with a coalescing runner #51381

Summary of the Pull Request

SupersedingAsyncGate handles command reloads, provider-cache saves and bookmark saves. These callers need one run at a time, with requests received during a run grouped into a follow-up run. They do not need the gate to cancel or supersede active work.

CoalescingAsyncRunner provides that simpler contract directly: one active batch and at most one pending batch, with each request completing with its batch's outcome. This removes cancellation and supersession bookkeeping while keeping pending requests reliable.

• Preserves pending requests and propagates each batch's outcome to its callers.


• Keeps loading state accurate across startup, reloads and provider activities, with reload completion notifications when the reload queue drains.


• Bounds provider-enable waits and publishes late results only while their load is still current.


• Lets bookmark and provider-cache owners drain accepted saves through asynchronous disposal.

PR Checklist

• [x] Closes: #51369
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• [ ] Communication: I've discussed this with core contributors already. If the work hasn't been agreed, this work might be rejected


• [ ] Tests: Added/updated and all pass


• [ ] Localization: All end-user-facing strings can be localized


• [ ] Dev docs: Added/updated


• [ ] New binaries: Added on the required places
  
  
  • [ ] JSON for signing for new binaries
  
  
  • [ ] WXS for installer for new binaries and localization folder
  
  
  • [ ] YML for CI pipeline for new test projects
  
  
  • [ ] YML for signed pipeline
    
  
  
  
  


• [ ] Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

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