feat(tabs): reuse an open tab instead of duplicating a page

- Add browser_cli/url_match.py with a canonical URL key for tab matching
- Canonicalize scheme, host, default ports, www., trailing slash, query order
- Support reuse modes none, exact, similar and origin via normalize_mode()
- Pick the closest match when several tabs qualify, preferring identical URLs
- Skip the reload when the reused tab already shows the requested page
- Expose nav.reusable_tab() so callers can look up a tab without side effects
- Accept reuse/reuse_domain/reuse_title in tabs.open(), not just nav.open()
- Add --reuse-exact to nav open and nav open-wait; --reuse is now fuzzy
- Default MCP tabs_open to reuse="similar" and return a reused flag
- Tell MCP agents in the server instructions to reuse before opening
- Document the reuse modes in README for MCP, CLI and Python API
- Cover url_match, SDK reuse paths and MCP reuse behaviour with new tests
- Bump package and extension version to 0.16.9
- Refresh uv.lock for the updated dependency set

extension/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "browser-cli",
-  "version": "0.16.8",
+  "version": "0.16.9",
   "description": "Control your browser from the terminal or Python SDK",
   "browser_specific_settings": {
     "gecko": {