fix(files_sharing): apply link share password on first save

Pre-declare newPassword on the share state so Vue 2's reactivity covers
it from the start. Without this, $set later relies on a
property-addition notification path that races with the toggle's async
setter and intermittently drops the password in certain build
environments.

Fixes: #57011
-e
Signed-off-by: Peter Ringelmann <peter.ringelmann@nextcloud.com>

apps/files_sharing/src/models/Share.ts

@@ -38,6 +38,10 @@ export default class Share {
 		}
 		ocsData.attributes = ocsData.attributes ?? []
 
+		// Pre-declared so Vue 2 makes newPassword reactive at observation time,
+		// avoiding $set's property-addition path which races with async setters.
+		ocsData.newPassword = ocsData.newPassword ?? undefined
+
 		// store state
 		this._share = ocsData
 	}
@@ -278,6 +282,18 @@ export default class Share {
 		this._share.password = password
 	}
 
+	/**
+	 * Unsaved password (set during share creation or editing).
+	 * Delegates to _share so reads/writes go through the reactive state.
+	 */
+	get newPassword(): string | undefined {
+		return this._share.newPassword
+	}
+
+	set newPassword(value: string | undefined) {
+		this._share.newPassword = value
+	}
+
 	/**
 	 * Password expiration time
 	 * @return {string} date with YYYY-MM-DD format