feat: add msedit-tzk customization suite

[kisaraki]

Summary

This PR proposes the msedit-tzk customization suite:

• add five selectable terminal themes, a white menu bar, and a green status bar
• present Find and Replace in centered dialogs with one option per row; fixed-width ASCII [ ]/[x] markers keep the complete outer frame intact across terminals
• add a clickable, foldable Markdown navigation pane for # through ######
• add boundary alignment and a bordered Open-dialog pane for five recent absolute paths
• start Open and untitled Save As from the portable Desktop directory
• separate the upstream 2.0.0 and tzk 0.0.8 version declarations
• add bilingual Chinese/English README documentation and paired bilingual comments for custom code
• add visible Windows and native WSL/Ubuntu build/deployment automation, including UAC/sudo notices and non-default Open With registration

Cross-platform design

• resolve Desktop and configuration locations through the portable dirs abstraction
• avoid direct platform APIs in custom application code
• remove the custom dependency on Windows COM and Shell features
• use fixed-width terminal text for checkbox layout on Windows, macOS, and Linux
• add native Windows, Ubuntu, and macOS CI matrix entries for tests, Clippy, and release builds
• keep WSL/Linux release artifacts on the configured shared data drive

Validation

• cargo fmt --all -- --check
• all Windows workspace tests passed; the edited binary suite reports 16 passed tests
• the ignored ICU runtime test passed explicitly
• Windows release build and UAC deployment passed under PowerShell 7.6.4
• native Ubuntu 26.04 WSL release build and sudo deployment passed
• Windows release/deployment SHA-256 matched: 5BA6251802B5EC76723085B343C2CDCA514F9B8A0220702432716039FBADC4B2
• WSL release/deployment SHA-256 matched: 6aa5dd8c7b4c7f8ce0a3f4a361d99cf33f164831772cb9ccf8c48c9a761e33ef
• cargo check -p edit --target x86_64-unknown-linux-gnu passed
• cargo check -p edit --target x86_64-apple-darwin passed
• existing .txt, .md, and .log default handlers remained unchanged
• recent-path opening, Markdown navigation, and complete Find/Replace dialog frames were verified in the GUI

Contribution and licensing

All modifications in this pull request are my own original personal work. They are unrelated to any organization or company and were not created in the course of employment. I have sole ownership of the intellectual-property rights to these submissions and agree to contribute them under the Microsoft Contributor License Agreement and the upstream project's MIT License. The kisaraki/edit customized build is also distributed under the MIT License.

This is a broad customization set and may be split into smaller upstream-focused changes if requested by the maintainers.

[kisaraki]

• (default - no company specified) I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer.

@microsoft-github-policy-service agree
I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer.

[kisaraki]

I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer.
@microsoft-github-policy-service agree

[kisaraki]

@microsoft-github-policy-service agree

[Leonard Hecker (lhecker)]

If you genuinely meant to submit this as a PR:

• We cannot merge PRs that change the copyright header
• If your PR is this big, it needs to either be discussed first, or split up into smaller PRs, each of which change one thing