fix(git): complete Git Log reference actions on Windows and macOS

[puppyben1]

Summary

• add the application context menu for Windows Git Log references
• expose the same applicable local, remote, and tag actions in the macOS Git Log context menu
• preserve complete Git reference identity through React/Swift, Tauri/Rust adapters, and shared Rust Core
• add shared checkout-and-rebase semantics with a clean-working-tree guard
• add explicit remote pull by rebase or merge without reconstructing refs as local branches
• add reference-to-working-tree comparison on Windows and current-branch comparison on both platforms
• block self checkout, merge, and rebase actions while keeping tag menus limited to supported operations
• add Windows English/Chinese strings, confirmations, progress disabling, notifications, refresh, and conflict reporting

Addresses all implementation items in #293.

Validation

• Rust Core comment verification passed
• Rust Core: 267 unit tests and 5 integration tests passed
• Windows Tauri Rust: 97 tests passed
• Windows frontend typecheck passed
• Windows frontend: 451 tests passed
• Windows Release build completed successfully
• test stability static gate passed
• git diff --check passed

Environment limitation

The current host is Windows and has no Swift or zsh toolchain, so scripts/test-macos.sh, the macOS timing harness, and Swift compilation could not be run locally. A deterministic macOS GitFeatureModel test was added for full remote reference identity and both pull strategies; macOS CI should execute it.

[1lck]

整体方向是对的，分层和完整 ref 传递也比较清楚。不过下面几个边界场景会直接影响功能正确性，建议合并前修掉。测试也建议从“只看参数”补到真实本地 remote 和实际菜单行为，这样后面排错会轻松很多。

[1lck]

这段流程继续放进 3400+ 行的 git/mod.rs，后面会越来越难维护，也不符合仓库的 facade 约定。建议移到 git/mutations.rs（或现有 owning module），这里保留 dispatch 就够了。

[1lck]

这条目前还没有完全解决：remote_branch_components 已经移到了 git/mutations.rs，但新增的 checkout_and_rebase 复合 mutation 流程仍然放在 git/mod.rs。请把这部分流程也移到 git/mutations.rs（或对应的 owning module），让 git/mod.rs 只保留 dispatch/facade；完成后再标记此讨论为 resolved。