fix: delete watcherMap when watcher is disposed

[pipiiiiii]

Types

• 🐛 Bug Fixes

Background or solution

🤖 Generated by Copilot at c0729dc

• Handle file watcher disposal on connection loss (link)

• Check if the original watcher is still valid using isDisposed() method (link)

• Add isDisposed() method to FileServiceWatcher class (link)

Issue: #2909

重连时 node 会 dispose watcher，但是前端没有处理，所以需要加个判断

Changelog

🤖 Generated by Copilot at c0729dc

This pull request improves the file service's resilience to connection loss by handling the disposal and recreation of file watchers. It modifies file-service-client.ts and watcher.ts to implement this logic.

[codecov]

Codecov Report

Patch coverage: 25.00% and project coverage change: -0.01 ⚠️

Comparison is base (ac1e2c7) 57.63% compared to head (65b276d) 57.62%.

Additional details and impacted files

@@            Coverage Diff             @@
##            v2.26    #2910      +/-   ##
==========================================
- Coverage   57.63%   57.62%   -0.01%     
==========================================
  Files        1337     1337              
  Lines       84130    84136       +6     
  Branches    17483    17485       +2     
==========================================
+ Hits        48485    48486       +1     
- Misses      32395    32400       +5     
  Partials     3250     3250              

Flag	Coverage Δ
jsdom	52.64% <25.00%> (-0.01%)	⬇️
node	16.79% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
packages/file-service/src/browser/watcher.ts	91.66% <0.00%> (-8.34%)	⬇️
...es/file-service/src/browser/file-service-client.ts	73.23% <33.33%> (-0.58%)	⬇️

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.