feat(release): publish to Chocolatey on release

[AThraen]

Summary

Implements #42 — publishes a Chocolatey package (codeshellmanager) alongside the existing winget release so Windows users can choco install codeshellmanager / choco upgrade codeshellmanager.

• Adds .chocolatey/ package skeleton: codeshellmanager.nuspec, tools/chocolateyinstall.ps1, tools/chocolateyuninstall.ps1, tools/LICENSE.txt, tools/VERIFICATION.txt.
• Adds .github/workflows/chocolatey.yml, triggered on release: released (mirroring winget.yml) and workflow_dispatch with a tag input for backfill / retry. The workflow downloads the signed MSI from the matching GitHub Release, computes its SHA256, substitutes __VERSION__ / __URL64__ / __CHECKSUM64__ placeholders, then choco pack and choco push to community.chocolatey.org using the CHOCO_API_KEY repo secret.
• README adds a Chocolatey install section and shields.io badge.
• CLAUDE.md gets a release-workflow note alongside the winget paragraph.

Open questions captured from the issue

• Moderator review — the first push to community.chocolatey.org is gated by manual moderator review. Subsequent versions auto-publish faster once the maintainer's account is trusted. The CHOCO_API_KEY is already in repo secrets.
• .portable package — not in scope for this PR (per the issue). The MSI variant covers Start Menu + uninstall via Apps & Features.
• Icon hosting — using raw.githubusercontent.com/umage-ai/CodeShellManager/main/src/CodeShellManager/Assets/app.ico. Chocolatey accepts this; if their moderation requests a PNG we can revisit.

Test plan

• workflow_dispatch the chocolatey workflow with tag: v0.5.0 after merging to verify packaging end-to-end against the most recent release.
• Monitor the moderation queue at https://community.chocolatey.org/packages/codeshellmanager for the initial submission.
• After approval, validate choco install codeshellmanager -y on a clean Windows VM and confirm Start Menu shortcut + uninstall via choco uninstall codeshellmanager.
• Cut a patch tag (vX.Y.Z) and confirm the workflow auto-fires on release: released.

🤖 Generated with Claude Code