Migrate dev-cli check-version to use ganda repo check-version

[StevenTCramer]

Background

ganda repo check-version has been implemented as a shared cross-repo version-check command with two strategies:

• --strategy git-tag — for GitHub releases (compares version to git tag)
• --strategy nuget-search --package <id> — for NuGet releases (checks NuGet.org via dotnet package search)

Required changes for this repo

1. Replace the inline check-version implementation (currently uses an HTTP call to v3-flatcontainer) with a thin delegation to ganda repo check-version:

int exitCode = await Shell.Builder("ganda")
  .WithArguments("repo", "check-version", "--strategy", "nuget-search",
    "--package", "TimeWarp.Terminal")
  .RunAsync(ct);

if (exitCode != 0) Environment.Exit(exitCode);
return Unit.Value;

2. Remove the inline HttpClient NuGet check and any RepoRootFinder/AppContext.BaseDirectory fallback root discovery.

3. Use Git.FindRoot() with no fallback anywhere root discovery is still needed.

Why

• Replaces the fragile HTTP v3-flatcontainer check with the standardized dotnet package search approach
• Eliminates divergent implementations across repos
• Single place to fix/improve the check logic

Reference

• ganda implementation: source/timewarp-ganda/endpoints/repo/repo-check-version-command.cs
• Analysis: timewarp-ganda .agent/workspace/2026-02-24T00-00-00_check-version-duplication-analysis.md

[StevenTCramer]

Updated Setup Instructions

Since the initial issue, ganda now supports config-driven check-version:

1. Set up check-version config for this repo:

   ganda config repo check-version --set --strategy nuget-search --package TimeWarp.Terminal

2. Ensure .timewarp/ is NOT in .gitignore — the config file .timewarp/ganda.jsonc should be committed to the repo

3. Then update dev-cli to delegate to ganda repo check-version (no arguments needed — reads config automatically)