Fix macOS build, resolve clippy warnings, add Windows ARM64

[Sekkyo]

This pull request introduces several improvements and fixes across the codebase, focusing on enhanced platform support, dependency updates, code simplification, bug fixes, and robustness improvements identified during code review. The most significant changes include fixing macOS builds by updating the zip crate configuration, adding Windows ARM64 build support, improving error handling and code clarity, fixing minor logic issues in the scraper and utility modules, and hardening the CBZ and PDF writers against silent failures and non-deterministic page ordering (Resolves #19).

Platform and Dependency Updates:

• Updated the zip crate to version 2.2.0, disabled default features, and enabled the deflate-miniz feature for more efficient and compatible CBZ/ZIP file creation. This is required for macOS compatibility (Cargo.toml).
• Added Windows ARM64 (aarch64-pc-windows-msvc) as a build target in the GitHub Actions release workflow, enabling distribution for more Windows devices (.github/workflows/release.yml).

Code Quality and Error Handling Improvements:

• Replaced deprecated or verbose error creation with the simpler io::Error::other and removed redundant doc comments, improving error handling throughout src/lib/scraper/helpers.rs. [1] [2]
• Simplified logic for extracting path segments using .next_back() instead of .last(), simplified generate_image_filename to a single format! call, and removed a redundant .to_string() call on a Cow<str>. [1] [2]

Scraper Logic and Bug Fixes:

• Removed unnecessary references and clones in function calls and variable assignments, reducing allocations and clarifying intent in src/lib/scraper/batching.rs and src/lib/scraper/scraper.rs. [1] [2] [3]
• Fixed logic for skipping pages without download links — the previous code had inverted None/Some checks that caused pages to be skipped incorrectly. Improved iteration over page children in metadata parsing by replacing a manual counter with e.text().enumerate(). [1] [2] [3]

Writer Robustness (from code review):

• Both create_cbz (src/lib/writer/cbz.rs) and create_pdf_internal (src/lib/writer/pdf.rs) now collect all read_dir entries eagerly via collect::<io::Result<_>>()?, propagating any entry-level I/O errors instead of silently dropping them with .flatten().
• Entries are sorted by filename before processing, ensuring stable and deterministic page ordering across all platforms (the zero-padded filename prefix 00001-, 00002-, etc. now reliably determines page sequence). [1] [2]
• File::open failures in create_cbz now propagate as io::Error instead of silently skipping pages, preventing the creation of incomplete archives without any indication of failure. [1]
• lopdf::xobject::image() failures in create_pdf_internal now propagate via map_err(...)? instead of being silently skipped via if let Ok(stream) = ..., preventing the creation of PDFs with missing pages. [1]
• doc.insert_image() errors now propagate with a descriptive message via io::Error::other(...) instead of printing "error!: {name}" and continuing. [1]
• content.encode(), filename into_string(), and path .to_str() conversions now return structured io::Error instead of panicking via .unwrap(). [1]

Utility and Miscellaneous:

• args.to_options().unwrap() in src/util/main.rs now matches on the result, printing to stderr and calling process::exit(1) on error. fs::read_to_string(file).unwrap() is replaced with ? propagation. [1] [2]
• Implemented the Default trait for TableOfContents in src/lib/writer/pdf.rs to satisfy Clippy's new_without_default lint. [1]
• Added #[allow(clippy::large_enum_variant)] to DownloadStatus and #[allow(clippy::module_inception)] to src/lib/scraper/mod.rs to suppress relevant Clippy warnings. [1] [2]
• Fixed typos in log messages ("Attemping" → "Attempting") and a comment ("propogation" → "propagation"). [1] [2]

[Copilot]

Pull request overview

This PR improves cross-platform builds and reduces Clippy noise while simplifying portions of the scraper and writer logic, including changes intended to fix macOS ZIP/CBZ creation and add Windows ARM64 release artifacts.

Changes:

• Update zip dependency configuration (v2.2.0, disable default features, enable deflate-miniz) and extend the release workflow matrix with aarch64-pc-windows-msvc.
• Refactor scraper helper/error conversion and simplify various scraper logic patterns (options handling, iteration, is_none() checks).
• Simplify writer directory iteration (using .flatten()) and add Default for TableOfContents.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
Cargo.toml	Updates zip crate configuration for improved compatibility (macOS build fix).
.github/workflows/release.yml	Adds Windows ARM64 target to release build matrix.
src/util/main.rs	Minor CLI/util parsing and result-handling cleanup.
src/lib/scraper/helpers.rs	Refactors Option/Result-to-io::Result helpers and URL/path utilities.
src/lib/scraper/batching.rs	Removes unnecessary references when calling helper functions.
src/lib/scraper/scraper.rs	Small logic simplifications around formats handling and page filtering.
src/lib/scraper/types.rs	Clippy allow for enum variant size + small parsing/iteration refactors.
src/lib/scraper/mod.rs	Adds Clippy suppression for module inception pattern.
src/lib/writer/cbz.rs	Simplifies directory iteration for CBZ creation.
src/lib/writer/pdf.rs	Adds Default for TOC and simplifies directory iteration for PDF creation.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[shloop]

Much appreciated! This was my first project in Rust and I have not used Rust much or done much of any software development outside of work since starting my current job, so it will probably take me a while to refresh my memory and properly review this. At a glance everything looks fine though, and if there are no issues I will merge once I get a chance to review.

[Sekkyo]

@shloop No worries, and Rust is such an excellent language to work with for a command line utility like this. I'm learning it through a lot of Agentic GitOps, but applying three decades of experience working in software development and enterprise architecture across private organizations and public sector. The Rust linter clippy and formatter rustfmt are your best friends. Run them before every commit and they will catch so many issues in a super opinionated language like Rust.

I'm working on these Copilot findings for you now and applying them to this pull request.

[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 6 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 2 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated no new comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Sekkyo]

@shloop Apologies for the long PR and many commits. I had to fix more things the longer Copilot kept giving me feedback. My first commit -- or maybe this repo always had -- a page sort order issue I reproduced last night and have now fixed. There's more files and lines of code to look at now, but I'm a lot happier with this result.

[shloop]

All looks good except for the part I commented on.