Drop the workspaceRoot parameter from resolveToolchainPaths /
Toolchain.resolvePaths entirely. The old code resolved
\`<workspaceRoot>/native/dugite/bin/git\` as the git binary before
falling back to PATH — a malicious repo could commit an executable
at that path and clide would run it on the first auto-fired
git.status (which fires automatically on workspace open).
Dugite now resolves against trusted locations only:
1. CLIDE_DUGITE_DIR env var (dev override).
2. <exe-parent>/dugite/bin/git (production bundle).
3. <exe-parent>/lib/dugite/bin/git (alternate bundle layout).
Test plants `native/dugite/bin/git` in a temp workspace and asserts
the resolved git path is NOT inside the workspace.
Callers updated (8 sites): main.dart, backend_entry.dart twice,
test_app.dart three times (compute now wraps a no-arg call), plus
five test fixtures. backend.dart's now-vestigial hintRoot left in
the struct for cleanup under T-99.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>