This commit updates `HashtagPreferencesService.decryptEvent` to register and utilize decryption methods from `window.nostr` (NIP-04 and NIP-44) as a fallback mechanism. This ensures that users without an active internal signer (e.g., read-only or extension-only users) can still decrypt their preferences if they have granted permission to the extension.
- Mirrors the decryption logic from `UserBlockListManager` (`js/userBlocks.js`).
- Adds logging for fallback attempts and failures.
- Preserves existing scheme selection logic (`determineDecryptionOrder`).
- Adds new test cases to `tests/hashtag-preferences.test.mjs` verifying fallback behavior when the active signer is missing or incapable.
Co-authored-by: PR0M3TH3AN <[email protected]>