Add quick reference guide for token storage

Co-authored-by: somalaya <[email protected]>

Author: Copilot

docs/TOKEN_STORAGE_QUICKREF.md

@@ -0,0 +1,74 @@
+# Token Storage Quick Reference
+
+> For comprehensive details, see [TOKEN_STORAGE_DOCUMENTATION.md](TOKEN_STORAGE_DOCUMENTATION.md)
+
+## Quick Summary
+
+### Where are tokens stored?
+**Android SharedPreferences** at:
+```
+/data/data/{package_name}/shared_prefs/com.microsoft.identity.client.account_credential_cache.xml
+```
+
+### What gets stored?
+- **AccountRecord**: User identity (username, IDs, name, etc.)
+- **AccessTokenRecord**: Access tokens with expiration, scopes, etc.
+- **RefreshTokenRecord**: Refresh tokens (MRRT/FRT)
+- **IdTokenRecord**: ID tokens with user claims
+
+### Storage Flow (Simplified)
+```
+BaseController.saveTokens()
+    ↓
+MsalOAuth2TokenCache.saveAndLoadAggregatedAccountData()
+    ↓
+SharedPreferencesAccountCredentialCache.saveAccount/saveCredential()
+    ↓
+SharedPreferencesFileManager.put() [with encryption]
+    ↓
+Android SharedPreferences (encrypted XML file)
+```
+
+### Cache Key Examples
+
+**Account Key:**
+```
+{homeAccountId}-{environment}-{realm}
+```
+
+**Access Token Key:**
+```
+{homeAccountId}-{environment}-accesstoken-{clientId}-{realm}-{scopes}
+```
+
+**Refresh Token Key:**
+```
+{homeAccountId}-{environment}-refreshtoken-{clientId}--
+```
+
+**ID Token Key:**
+```
+{homeAccountId}-{environment}-idtoken-{clientId}-{realm}-
+```
+
+### Security
+- ✅ Values are **encrypted** using Android KeyStore
+- ✅ Keys are **hardware-backed** on supported devices  
+- ✅ Files are **app-private** (MODE_PRIVATE)
+- ✅ **In-memory LRU cache** (256 entries) for performance
+- ✅ Broker mode uses **UID-sequestered** caches per app
+
+### Key Code Locations
+- Entry point: `BaseController.saveTokens()` (line 903)
+- Cache logic: `MsalOAuth2TokenCache.java`
+- Key generation: `CacheKeyValueDelegate.java`
+- Storage: `SharedPreferencesFileManager.java`
+- DTOs: `dto/` package (AccountRecord, AccessTokenRecord, etc.)
+
+### Special Files
+- **FOCI Cache**: `...cache.foci-1` (Family Refresh Tokens)
+- **UID Cache**: `...cache.uid-{uid}` (Per-app broker cache)
+
+---
+
+📖 **Full Documentation**: [TOKEN_STORAGE_DOCUMENTATION.md](TOKEN_STORAGE_DOCUMENTATION.md)