[Oztechan/AdTrack#171] Reset iOS premium on reinstall (move premium off Keychain)

[mustafaozhan]

Closes #171. Sub-task of #121.

Problem

On iOS, premium shared the Keychain-backed SecureStorage with auth tokens. The Keychain survives app uninstall, so a granted premium window persisted across reinstall — inconsistent with Android, where all app storage is wiped on uninstall.

Fix

• New PreferenceStorage — a sandbox-scoped, uninstall-wiped key/value store, deliberately not Keychain-backed.
  • iOS: backed by NSUserDefaults (wiped on uninstall, unlike the Keychain) → premium now resets on reinstall.
  • Android: reuses the existing store; Android already wipes app data on uninstall, so behaviour is unchanged there. The change is wiring only (the shared PremiumManagerImpl now needs this type on both platforms).
• PremiumManagerImpl depends on PreferenceStorage instead of SecureStorage.
• Auth tokens are untouched — they stay in Keychain-backed SecureStorage, so users stay logged in across reinstall.
• DI/test support + affected Koin/manager tests updated.

Verified

• :common:testDebugUnitTest + :common:detektAll green.
• :common:compileKotlinIosSimulatorArm64 green (NSUserDefaults binding resolves).

Note: no production users yet, so no in-flight premium windows are affected.

[codecov]

Codecov Report

❌ Patch coverage is 83.33333% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 63.42%. Comparing base (0c226ef) to head (f3e3420).
⚠️ Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
...oztechan/adtrack/core/storage/PreferenceStorage.kt	75.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #172      +/-   ##
===========================================
- Coverage    63.63%   63.42%   -0.21%     
===========================================
  Files           69       70       +1     
  Lines         1031     1036       +5     
  Branches       115      115              
===========================================
+ Hits           656      657       +1     
- Misses         321      325       +4     
  Partials        54       54              

Files with missing lines	Coverage Δ
.../com/oztechan/adtrack/di/PlatformModule.android.kt	31.25% <100.00%> (+4.58%)	⬆️
...oztechan/adtrack/ads/premium/PremiumManagerImpl.kt	100.00% <100.00%> (ø)
...oztechan/adtrack/core/storage/PreferenceStorage.kt	75.00% <75.00%> (ø)

... and 1 file with indirect coverage changes

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