uploads: locked-storage file picks unlock inline instead of dead-ending (#56)

All three paths (upload video pick, upload thumbnail pick, edit "Replace
file") now route through the shared signer gate — silent kept-unlocked
restore, else ONE passphrase prompt — then unlock storage and continue the
same pick. Cancel/bad-passphrase abort quietly; a refused thumbnail pick
restores the picker. Unlock glue extracted to uploadModalStorageUnlock.js
(file-size budget); ensureSigner threaded via initUploadModal/initEditModal.

Tests: tests/upload-edit-storage-unlock-gate.test.mjs (12).

Co-Authored-By: Claude Fable 5 <[email protected]>

js/ui/initUploadModal.js

@@ -61,6 +61,12 @@ export function initUploadModal({
           app.profileController.show("storage");
         }
       },
+      // Shared signer gate (#56): restores a kept-unlocked key silently or shows
+      // one passphrase prompt so the file pickers can unlock storage inline.
+      ensureSigner: (options) =>
+        typeof app?.ensureEncryptionCapableSigner === "function"
+          ? app.ensureEncryptionCapableSigner(options)
+          : null,
       // Open the login modal's unlock-saved-key (passphrase) flow when a persisted
       // nsec session is locked after a reload.
       onRequestUnlock: () => {