[REF] refactor file pool model and imports

- Refactor SnFilePool using freezed + sealed for consistency with other Sn models
- Add extension method listFromResponse for PoolService compatibility
- Update PoolService and utils to use SnFilePool
- Replace relative imports (../) with package imports for clarity and maintainability

Signed-off-by: Texas0295 <kimura@texas0295.top>

lib/screens/account/profile.g.dart

@@ -268,7 +268,7 @@ class _AccountBadgesProviderElement
 }
 
 String _$accountAppbarForcegroundColorHash() =>
-    r'8ee0cae10817b77fb09548a482f5247662b4374c';
+    r'127fcc7fd6ec6a41ac4a6975276b5271aa4fa7d0';
 
 /// See also [accountAppbarForcegroundColor].
 @ProviderFor(accountAppbarForcegroundColor)

lib/screens/auth/captcha.config.g.dart

@@ -6,7 +6,7 @@ part of 'captcha.config.dart';
 // RiverpodGenerator
 // **************************************************************************
 
-String _$captchaUrlHash() => r'bbed0d18272dd205069642b3c6583ea2eef735d1';
+String _$captchaUrlHash() => r'd46bc43032cef504547cd528a40c23cf76f27cc8';
 
 /// See also [captchaUrl].
 @ProviderFor(captchaUrl)

lib/screens/posts/pub_profile.g.dart

@@ -400,7 +400,7 @@ class _PublisherSubscriptionStatusProviderElement
 }
 
 String _$publisherAppbarForcegroundColorHash() =>
-    r'd781a806a242aea5c1609ec98c97c52fdd9f7db1';
+    r'cd9a9816177a6eecc2bc354acebbbd48892ffdd7';
 
 /// See also [publisherAppbarForcegroundColor].
 @ProviderFor(publisherAppbarForcegroundColor)

lib/screens/realm/realm_detail.g.dart

@@ -7,7 +7,7 @@ part of 'realm_detail.dart';
 // **************************************************************************
 
 String _$realmAppbarForegroundColorHash() =>
-    r'14b5563d861996ea182d0d2db7aa5c2bb3bbaf48';
+    r'8131c047a984318a4cc3fbb5daa5ef0ce44dfae5';
 
 /// Copied from Dart SDK
 class _SystemHash {

lib/screens/settings.dart

@@ -373,7 +373,7 @@ class SettingsScreen extends HookConsumerWidget {
       poolsAsync.when(
         data: (pools) {
           final validPools = filterValidPools(pools);
-          final currentPoolId = resolveDefaultPoolId(ref, pools);
+          final currentPoolId = resolveDefaultPoolId(ref, validPools);
 
           return ListTile(
             isThreeLine: true,
@@ -392,12 +392,14 @@ class SettingsScreen extends HookConsumerWidget {
               child: DropdownButton2<String>(
                 isExpanded: true,
                 items:
-                    validPools.map((p) {
-                      return DropdownMenuItem<String>(
-                        value: p.id,
-                        child: Text(p.name).fontSize(14),
-                      );
-                    }).toList(),
+                    validPools
+                        .map(
+                          (p) => DropdownMenuItem<String>(
+                            value: p.id,
+                            child: Text(p.name).fontSize(14),
+                          ),
+                        )
+                        .toList(),
                 value: currentPoolId,
                 onChanged: (value) {
                   ref