Fix Windows argument encoding by fetching UTF-8 command line

[alaotach]

[FIX] Resolve Windows ANSI argument mangling for non-ASCII paths

In raising this pull request, I confirm the following (please check boxes):
Reason for this PR:

• This PR adds new functionality.
• This PR fixes a bug that I have personally experienced or that a real user has reported and for which a sample exists.
• This PR is porting code from C to Rust.

Sanity check:

• I have read and understood the contributors guide.
• I have checked that another pull request for this purpose does not exist.
• If the PR adds new functionality, I've added it to the changelog. If it's just a bug fix, I have NOT added it to the changelog.
• I am NOT adding new C code unless it's to fix an existing, reproducible bug.

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Fixes

Closes #2284

Problem

On Windows, the standard main(int argc, char *argv[]) entry point receives arguments encoded in the system's local legacy ANSI code page (e.g., CP-1252), not UTF-8.
indows ANSI argument mangling for non-ASCII paths

In raising this pull request, I confirm the following (please check boxes):
Reason for this PR:

• This PR adds new functionality.
• This PR fixes a bug that I have personally experienced or that a real user has reported and for which a sample exists.
• This PR is porting code from C to Rust.

Sanity check:

• I have read and understood the contributors guide.
• I have checked that another pull request for this purpose does not exist.
• If the PR adds new functionality, I've added it to the changelog. If it's just a bug fix, I have NOT added it to the changelog.
• I am NOT adding new C code unless it's to fix an existing, reproducible bug.

---

Fixes

Closes #2284

Problem

On Windows, the standard main(int argc, char *argv[]) entry point receives arguments encoded in the system's local legacy ANSI code page (e.g., CP-1252), not UTF-8.

When these arguments are passed to the new Rust parameter parser (ccxr_parse_parameters), Rust strictly expects UTF-8 strings and attempts to parse them using to_string_lossy(). Because non-ASCII ANSI characters (like the £ symbol, which is 0xA3) are invalid UTF-8 byte sequences, they get gracefully replaced with the Unicode Replacement Character (U+FFFD). When printed back to the console, this manifests as mangled, permanently mangling the file path and preventing CCExtractor from opening the file.

Fix

Added a Windows-specific #ifdef _WIN32 block at the very top of main() in ccextractor.c to intercept and sanitize the arguments.

It uses the native Windows APIs GetCommandLineW() and CommandLineToArgvW() to fetch the raw UTF-16 Unicode command line, safely converts the wide strings to standard UTF-8 using WideCharToMultiByte(), and dynamically overrides the legacy argv array before it is passed to the rest of the application.

This perfectly preserves all non-ASCII characters without changing the Rust API, breaking backwards compatibility for libraries, or changing the main entry point signature.

Repro instructions

1. On a standard Windows installation without global UTF-8 beta features enabled, rename any video file to include the £ symbol. Example: £5 Million Restoration.ts.
2. Run CCExtractor against it: ccextractorwinfull.exe "£5 Million Restoration.ts".
3. Before fix: CCExtractor fails with Error: Failed to open one of the input file(s): File does not exist. and prints the mangled input file name as �5 Million Restoration.ts.
4. After fix: CCExtractor successfully parses the £ symbol, natively locates the file, and proceeds to extract the captions.