Refactor and update various components of EchoHub.Server

- Updated launchSettings.json for consistency.
- Refactored FileValidationHelper to improve image validation logic.
- Enhanced ServerDirectoryService for better connection handling and user count updates.
- Improved DatabaseSetup for legacy database handling and seeding default channels.
- Refined FirstRunSetup to ensure JWT secret generation.
- Removed appsettings.Development.json as it is no longer needed.
- Updated EchoHub.Tests project file for consistency.
- Added unit tests for FileValidationHelper and PresenceTracker with improved assertions.
- Updated ValidationConstantsTests to ensure regex validations are correct.
- Cleaned up solution file formatting for better readability.

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,28 +1,28 @@
-# Summary
-
-<!-- What does this PR change, and why? Keep it brief. -->
-
-## Changes
-
-- Describe the changes here
-
-## Screenshots / recordings (optional)
-
-<!-- If you changed the TUI UI/UX, add a screenshot or short recording. -->
-
-## How to test
-
-- [ ] `dotnet build src/EchoHub.slnx`
-- [ ] `dotnet test src/EchoHub.slnx`
-
-## Checklist
-
-- [ ] I ran tests locally (or explained why not)
-- [ ] I kept changes focused and easy to review
-- [ ] I updated docs where needed (README/docs)
-- [ ] I verified no secrets/keys are committed
-- [ ] If this touches files/uploads/auth, I considered security implications
-
-## Related issues
-
-- Closes #
+# Summary
+
+<!-- What does this PR change, and why? Keep it brief. -->
+
+## Changes
+
+- Describe the changes here
+
+## Screenshots / recordings (optional)
+
+<!-- If you changed the TUI UI/UX, add a screenshot or short recording. -->
+
+## How to test
+
+- [ ] `dotnet build src/EchoHub.slnx`
+- [ ] `dotnet test src/EchoHub.slnx`
+
+## Checklist
+
+- [ ] I ran tests locally (or explained why not)
+- [ ] I kept changes focused and easy to review
+- [ ] I updated docs where needed (README/docs)
+- [ ] I verified no secrets/keys are committed
+- [ ] If this touches files/uploads/auth, I considered security implications
+
+## Related issues
+
+- Closes #