chore: make autoRequestProfileForMissingUsers and getDisplayNameAndAvatarFromPrevContent configurable

[krille-chan]

Note

Low Risk
Behavioral toggles default to existing behavior; risk is mainly misconfiguration (fewer profile fetches or missing display names for left users).

Overview
Adds two Client constructor flags so apps can tune how missing room members are resolved without changing call sites everywhere.

autoRequestProfileForMissingUsers (default true) drives whether Room.requestUser falls back to the global profile when member state is empty. requestProfile is now optional; when omitted it uses that client setting.

getDisplayNameAndAvatarFromPrevContent (default true) gates whether User.displayName and User.avatarUrl still read from prevContent for non-joined members (e.g. left or banned). Turning it off stops using stale names/avatars from prior member events while keeping current defaults.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.45%. Comparing base (21d1285) to head (f03a1f6).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2472   +/-   ##
=======================================
  Coverage   60.44%   60.45%           
=======================================
  Files         162      162           
  Lines       20568    20572    +4     
=======================================
+ Hits        12432    12436    +4     
  Misses       8136     8136           

Files with missing lines	Coverage Δ
lib/src/client.dart	78.33% <ø> (ø)
lib/src/room.dart	78.32% <100.00%> (+0.03%)	⬆️
lib/src/user.dart	90.65% <100.00%> (+0.17%)	⬆️

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[td-famedly]

oki

[td-famedly]

@cursor review

[cursor]

✅ Bugbot reviewed your changes and found no new issues!

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^{Reviewed by Cursor Bugbot for commit f03a1f6. Configure here.}