Function resolve_all 

pub fn resolve_all(
    manifest: &ProjectManifest,
    project_root: &Path,
    ci_mode: bool,
) -> ResolveReport

Resolve all plugins declared in a project manifest.

For each plugin:

1. Check if already installed with a satisfying version
2. Based on source scheme, download or build
3. Verify integrity (sha256 for downloads)
4. Install to .ta/plugins/<type>/<name>/

ci_mode: If true, treat optional plugin failures as hard errors.