Add inline links option to plugin

[joshhbk]

Summary

• Adds a links option to LocaldevPluginOptions so consumers can pass a Record<string, string> (package name → local path) directly to the plugin without needing the CLI, .localdev.json, or heartbeat
• When inline links are provided, resolution is always active — no CLI session required
• Extracts Vite lifecycle setup (setupCliLifecycle, watchLinkedOutputDirs) out of the configureServer hook into named helpers

Usage

import { localdev } from "localdev/vite";

export default {
  plugins: [
    localdev({ links: { "@acme/ui": "../packages/ui" } }),
  ],
};

Test plan

• Existing tests pass (68/68)
• New test: resolves with inline links and no heartbeat
• New test: returns null for non-linked import with inline links
• Manual: wire up inline links in a Vite project and verify resolution works without localdev start