Allow key verification to work for unknown nodes. (#10669)

* Allow key verification to work for unknown nodes.

* trunk

* More reliable admin key decryption

* Add admin key fallback tests

* Actually check haveRemoteKey

* Logging cleanup

* Address review feedback

- Persist the committed key + manually-verified flag in
  commitVerifiedRemoteNode via saveToDisk(SEGMENT_NODEDATABASE),
  replacing the "todo: initiate save"
- Guard the CryptoEngine pending-key slot with a dedicated internal
  lock; the Router reads it while already holding the non-recursive
  cryptLock, so the accessors cannot reuse that lock
- Draw the security number from the hardware RNG (CryptRNG fallback)
  under cryptLock instead of random(); on nRF52 the entropy fill
  toggles the same CC310 the BLE task's packet crypto uses
- Return true after fully handling the hash2 response (restores
  develop behavior; consistent with the hash1 branch)
- Take uint32_t in the number-picker callbacks so 8-digit hex
  nodenums can't truncate through int
- Trim over-long comments flagged by review

* feat(tests): add deterministic tests for admin session-key behavior

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/graphics/Screen.cpp

@@ -343,7 +343,7 @@ void Screen::showNodePicker(const char *message, uint32_t durationMs, std::funct
 }
 
 // Called to trigger a banner with custom message and duration
-void Screen::showNumberPicker(const char *message, uint32_t durationMs, uint8_t digits,
+void Screen::showNumberPicker(const char *message, uint32_t durationMs, uint8_t digits, bool useBase16,
                               std::function<void(uint32_t)> bannerCallback)
 {
 #ifdef USE_EINK
@@ -356,7 +356,10 @@ void Screen::showNumberPicker(const char *message, uint32_t durationMs, uint8_t
     NotificationRenderer::alertBannerCallback = bannerCallback;
     NotificationRenderer::pauseBanner = false;
     NotificationRenderer::curSelected = 0;
-    NotificationRenderer::current_notification_type = notificationTypeEnum::number_picker;
+    if (useBase16)
+        NotificationRenderer::current_notification_type = notificationTypeEnum::hex_picker;
+    else
+        NotificationRenderer::current_notification_type = notificationTypeEnum::number_picker;
     NotificationRenderer::numDigits = digits;
     NotificationRenderer::currentNumber = 0;