features: add commit and push option to git commit window

- Add split button with dropdown in commit dialog supporting both
  "Commit" and "Commit and Push" actions
- Pass folderId through gitCommit/gitPush API calls so backend emits
  events that the folder window can receive for toast notifications
- Update Tauri git_commit and git_push commands to accept folder_id
  parameter with window label fallback for cross-window compatibility
- Wrap commit page with GitCredentialProvider for push authentication
- Keep commit window open when push fails so user can see the error
- Add i18n translations for all 10 locales

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lib/api.ts

@@ -574,12 +574,14 @@ export async function gitPushInfo(path: string): Promise<GitPushInfo> {
 export async function gitPush(
   path: string,
   remote?: string | null,
-  credentials?: GitCredentials | null
+  credentials?: GitCredentials | null,
+  folderId?: number | null
 ): Promise<GitPushResult> {
   return getTransport().call("git_push", {
     path,
     remote: remote ?? null,
     credentials: credentials ?? null,
+    folderId: folderId ?? null,
   })
 }
 
@@ -886,9 +888,15 @@ export async function gitIsTracked(
 export async function gitCommit(
   path: string,
   message: string,
-  files: string[]
+  files: string[],
+  folderId?: number | null
 ): Promise<GitCommitResult> {
-  return getTransport().call("git_commit", { path, message, files })
+  return getTransport().call("git_commit", {
+    path,
+    message,
+    files,
+    folderId: folderId ?? null,
+  })
 }
 
 export async function gitRollbackFile(