feat(mcp): target DOM tools by tab

- Add server-side search filtering to the MCP tabs_list tool.
- Let MCP DOM query, click, and type tools operate on an explicit tab_id.
- Use tab-scoped DOM eval fallbacks when the SDK active-tab helpers are not enough.
- Cover tab filtering and tab-targeted DOM operations in MCP tests.
- Bump package and extension versions to 0.16.8 and refresh the lockfile.

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "real-browser-cli"
-version = "0.16.7"
+version = "0.16.8"
 description = "Control your real running browser from the terminal or Python SDK"
 readme = "README.md"
 license = { file = "LICENSE" }