Fix CSV import file-handle error handling

[mlintangmz2765]

Motivation

• Prevent runtime warnings or fatal errors when an uploaded CSV cannot be opened by guarding fopen() and returning with a clear error message.
• Ensure the uploaded-file state and file handle are always cleaned up even when exceptions occur during import.
• Remove an unused variable to keep the implementation cleaner.

Description

• Add a guard after fopen($path, 'r') that sets an error message and returns early if the handle is false to avoid operating on an invalid resource.
• Move fclose($handle) and $this->file_csv = null into a finally block so cleanup always runs whether the import succeeds or an exception is thrown.
• Remove the unused $errors counter from the method.
• Keep existing CSV parsing, date parsing, contact sync and Postcard creation logic unchanged.

Testing

• Ran php -l app/Livewire/ImportPostcards.php which reported no syntax errors and confirmed the modified file is valid.
• Attempted to run the test suite with php artisan test but the environment could not install Composer dependencies due to network/GitHub access errors, so the full automated test suite could not be executed.

---

Codex Task

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 0e5fdb49c6

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Clear uploaded file state before early return

If fopen() fails, this new early return exits before the cleanup in finally, so $this->file_csv is never reset on this error path. In Livewire, keeping the file-bound property populated after a failed upload can block straightforward retry flows (especially re-selecting the same file), causing repeated import failures until the component is refreshed. Route this branch through shared cleanup or explicitly reset $this->file_csv before returning.

Useful? React with 👍 / 👎.