[BUG] Plugin dependency version doesn't work at all

Summary

The plugin dependency version resolution system (using git tags like {name}--v{version}) does not work at all.

I have tested this on v2.1.159

Current Behavior

I created a plugin with a specific dependency:

$ cat ./plugins/bundle-test/.claude-plugin/plugin.json 

{
  "name": "bundle-test",
  "version": "0.1.0",
  "description": "Test plugin for bundled dependencies",
  "author": {
    "name": "stbenjam"
  },
  "dependencies": [
    {
      "name": "jira",
      "marketplace": "ai-helpers",
      "version": "=0.5.0"
    }
  ]
}

Expected Behavior

The plugin loader should:

1. Read the dependency version constraint (jira version 0.5.0)
2. Check if a git tag jira--v0.5.0 exists in the openshift-eng/ai-helpers marketplace
3. Check out/extract that specific version to satisfy the dependency
4. Install the correct version

This should work regardless of whether the plugins are being installed from a remote repository or from a local git repository.

Steps to Reproduce

$ export CLAUDE_CONFIG_DIR=$(mktemp -d)
$ claude plugin marketplace add stbenjam/temp-marketplace
$ claude plugin marketplace add openshift-eng/ai-helpers 
$ claude plugin install bundle-test@test-marketplace

Expected Results

0.5.0 gets installed (which is the hard dep of "bundle test"

Actual Results

The latest version is installed (0.6.0)

Installed plugins:

  ❯ bundle-test@test-marketplace
    Version: 0.1.0
    Scope: user
    Status: ✘ failed to load
    Error: Requires "jira@ai-helpers" 0.5.0, installed 0.6.0

  ❯ jira@ai-helpers
    Version: 0.6.0
    Scope: user
    Status: ✔ enabled

Why This Matters

The docs say this works. It doesn't. https://code.claude.com/docs/en/plugin-dependencies#tag-plugin-releases-for-version-resolution

Note: I have tried both "=0.5.0" and "0.5.0" by itself.