fix: deep dive audit fixes, browser split, error standardization, PSP warnings

[AndrewAltimit]

Summary

• Bug fixes: Atomic memory ordering (Relaxed->Release/Acquire) in streaming buffer, moov overwrite race in download.rs, PSP video codec EDRAM leak, overlay stride validation, SDL3 Cargo.toml description, FFI safety documentation
• Browser lib.rs split: Extract 2,320-line test module to browser_tests.rs (lib.rs: 2,771->451 lines)
• Error handling standardization: Convert VideoError, LiteError, JsError, CalcError from manual Display/Error impls to thiserror derives; add Video/JavaScript/Calc variants to central OasisError; CalcError gains first std::error::Error impl
• PSP EBOOT warnings eliminated (50->0): Wrap unsafe calls in inner unsafe blocks (Rust 2024), dead_code on legacy chrome/theme modules, remove unused imports/features
• PSP Plugin PRX warnings eliminated (8->0): Remove unused imports, suppress unused-assignment, dead_code on utilities
• Screenshots regenerated for all 19 skins

Test plan

• cargo build --workspace passes
• cargo test --workspace -- all tests pass
• cargo clippy --workspace -- -D warnings -- clean
• cargo fmt --all -- --check -- clean
• PSP EBOOT builds with 0 warnings
• PSP Plugin PRX builds with 0 warnings
• WASM release build passes
• All 19 skin screenshots regenerated

Generated with Claude Code (https://claude.com/claude-code)

[github-actions]

Gemini AI Code Review

Issues (if any)

(none)

Previous Issues (for incremental reviews)

(none)

Suggestions (if any)

• crates/oasis-backend-psp/src/chrome.rs:2 - Using #![allow(dead_code)] at the module level suppresses warnings for the entire file. If this module is still actively modified, consider scoping the attribute to the specific legacy items to ensure new dead code is still flagged.

Notes

• Excellent transition to thiserror across oasis-app-calculator, oasis-js, and oasis-video. It significantly reduces boilerplate and standardizes the error variants in OasisError.
• The atomic memory ordering fixes (Relaxed -> Release/Acquire) in download.rs and streaming_buffer.rs correctly enforce the necessary happens-before synchronization between the download state and the reader thread.
• The stride validation (stride > render::MAX_STRIDE) in the PSP overlay is a good defensive programming measure to prevent integer overflow and out-of-bounds memory access in on_frame.
• Rust 2024 edition requirements for explicit unsafe blocks inside unsafe fn were properly applied to the PSP HTTP module.
• BrowserWidget lib split correctly preserves functionality while massively reducing file length.

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Generated by Gemini AI (gemini-3.1-pro-preview). Supplementary to human reviews.

[AndrewAltimit]

Review Response Agent (Iteration 1)

Status: No changes needed

Fixed Issues

• (none)

Ignored Issues

• crates/oasis-backend-psp/src/chrome.rs:2 — Gemini suggested scoping #![allow(dead_code)] to specific items instead of module-level. This is a minor style preference for a PSP plugin module that is excluded from the workspace (cargo build --workspace skips it). The module has many conditionally-used items for dashboard/chrome rendering, and scoping the allow to individual items would add significant noise with no practical benefit since new dead code in this file wouldn't indicate bugs.

Deferred to Human

• (none)

Notes

• The Gemini review found zero issues and rated the PR positively. The only suggestion was a minor style preference about dead_code allow scope in the PSP plugin, which is not actionable given the nature of that codebase.
• The review praised: thiserror migration, atomic ordering fixes (Relaxed→Release/Acquire), PSP stride validation, Rust 2024 unsafe block compliance, and BrowserWidget split.

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The agent reviewed feedback but determined no code changes were required.