Treat Vue routes as first-class MCP resources

### Epic

_No response_

### Description

UI navigation via the expert sits at roughly 80% success rate. The root cause is that routes are opaque to the LLM: no descriptions, no tags, no way to filter, and inconsistent naming.

The end goal is to make Vue routes proper MCP resources so clients can reason about them contextually. There are also some functional issues to address: sometimes ui_navigate returns success but the UI doesn't react, and navigating to the same page with the same attributes should throw rather than silently succeed.

This breaks down into a few incremental steps, ordered from least to most intrusive

### Which customers would this be available to

None

### Acceptance Criteria

_No response_

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate

Start by tracing the Vue route handling and the ui_navigate entry point. The issue provides no file or test names and no acceptance criteria, so confirm the incremental steps and expected behavior with maintainers before identifying completion tests.

Written by the indexing model from the issue text.