Clear openfile before unwinding the history, not after

[skjnldsv]

Closing the viewer unwinds the history entries it pushed with history.go(-offset), which lands on a later task. Until it lands the URL still carries openfile=true, and FilesListVirtual.handleOpenQueries() runs the default action for exactly that flag. Anything that makes the Files list re-read the route inside that window opens a second viewer over the one that is closing.

It shows up on a shared CI runner, where the window is wide enough to hit. Three media tests in nextcloud/server#63954 failed their close assertion, all the same way:

Error: expect(locator).toBeHidden() failed
Locator: locator('.viewer__modal').locator('.modal-container')
  4 × locator resolved to <div class="modal-container" id="modal-description-nc-vue-6">
 10 × locator resolved to <div class="modal-container" id="modal-description-nc-vue-8">

Two containers, one per viewer instance. Probing the DOM against a real server shows the window plainly: right after the close button is clicked there is still one modal and the URL still says openfile=true; a second later the modal is gone and the flag with it.

OPEN     roots:1 containers:1 mounts:1   url=…/files/26?dir=/&openfile=true
CLICKED  roots:1 containers:1 mounts:1   url=…/files/26?dir=/&openfile=true
SETTLED  roots:0 containers:0 mounts:1   url=…/files

The flag now comes off the entry being left before the jump is requested, so there is no window where the URL asks for a file that the viewer is busy closing. The refresh-opened case already did this and is unchanged.

The new unit test pins the order rather than just the outcome: goToRoute before history.go, since doing it the other way round is what the bug was. It fails on main.

👾 This pull request was assisted by Claude Code, commits carry an Assisted-by trailer.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.99%. Comparing base (95e0fd6) to head (518c343).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #43   +/-   ##
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  Coverage   87.99%   87.99%           
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  Files          36       36           
  Lines        2507     2508    +1     
  Branches      524      525    +1     
=======================================
+ Hits         2206     2207    +1     
  Misses        297      297           
  Partials        4        4           

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