docs: enhance documentation with threat model, limitations, air-gapped guidance

- Update version to v1.4.4
- Add explicit threat model documentation
- Document known limitations prominently
- Include air-gapped usage recommendations
- Polish all documentation for clarity and examples
- Update README, DEVELOPMENT.md, GEMINI.md, RECOVERY_PLAYBOOK.md

src/lib/types.ts

@@ -12,3 +12,39 @@ export type ParsedSeedPgpFrame = {
     crc16: string;
     b45: string;
 };
+
+// Krux KEF types
+export type KruxEncryptionParams = {
+    label?: string;
+    iterations?: number;
+    version?: number;
+};
+
+export type EncryptionMode = 'pgp' | 'krux';
+
+export type EncryptionParams = {
+    plaintext: SeedPgpPlaintext | string;
+    publicKeyArmored?: string;
+    messagePassword?: string;
+    mode?: EncryptionMode;
+    kruxLabel?: string;
+    kruxIterations?: number;
+    kruxVersion?: number;
+};
+
+export type DecryptionParams = {
+    frameText: string;
+    privateKeyArmored?: string;
+    privateKeyPassphrase?: string;
+    messagePassword?: string;
+    mode?: EncryptionMode;
+};
+
+export type EncryptionResult = {
+    framed: string;
+    pgpBytes?: Uint8Array;
+    recipientFingerprint?: string;
+    label?: string;
+    version?: number;
+    iterations?: number;
+};