feat(tools-browser): set_default_browser / use_browser actions for v1.9.0 bridge

The extension's bridge server (cdp-bridge-server.ts v1.9.0) added two
new actions for dynamic browser switching:

  set_default_browser — persist a default-target browser
  use_browser        — alias of set_default_browser

Both accept the browser name (firefox / chrome / safari / edge or a
specific instance ID like 'firefox-2') as the 'browser' field. The
bridge writes the choice to ~/.hanzo/extension/config.json so it
survives bridge restarts.

This commit:
- Adds the two action names to the Action Literal so the MCP tool
  accepts them.
- Adds them to extension_actions so they route through the bridge
  rather than falling to Playwright.
- The 'target_browser' parameter (already exposed) carries the
  browser name through to the bridge as 'browser', which is exactly
  what set_default_browser expects.

Bumps hanzo-tools-browser 0.4.5 → 0.4.6.

pkg/hanzo-tools-browser/hanzo_tools/browser/browser_tool.py

@@ -394,6 +394,8 @@ Action = Annotated[
         "tabs",  # list/switch tabs
         "select_tab",  # bring a specific tab to focus (Target.activateTarget)
         "list_browsers",  # list every connected extension provider
+        "set_default_browser",  # persist the bridge's default browser pick
+        "use_browser",  # alias of set_default_browser
         "connect",  # connect via CDP
         "set_headless",  # toggle headless/headed
         "status",  # get browser status
@@ -884,6 +886,10 @@ CATEGORIES:
             "inject_script", "inject_css",
             "local_storage", "cookies",
             "tabs", "new_tab", "select_tab",
+            # Multi-browser routing (bridge v1.9.0+) — list connected
+            # providers and persist a default-browser pick. Without one
+            # the bridge auto-prefers firefox > safari > edge > chrome.
+            "list_browsers", "browsers", "set_default_browser", "use_browser",
             "console", "network_requests", "status",
             # Takeover actions (Phase 3)
             "takeover", "release",

pkg/hanzo-tools-browser/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "hanzo-tools-browser"
-version = "0.4.5"
+version = "0.4.6"
 description = "Browser automation tools with extension-first routing - uses Hanzo browser extension when available, Playwright as fallback"
 readme = "README.md"
 requires-python = ">=3.12"