feat!: harden raw browser control and packaging

- Add safe-by-default policy gates for raw command surfaces: command, script, and serve-http /command.

- Require explicit opt-ins for page reads, browser control, and high-risk commands such as dom.eval, storage.*, and screenshots.

- Remove all cookies support from CLI, SDK, extension commands, permissions, constants, docs, and tests.

- Add diagnostic, events, watch, workspace, remote, raw command, script, HTTP gateway, tree-view, session import/export, and extension info/capability commands.

- Add Chrome Web Store packaging that strips manifest.key while keeping local packages with a stable native-messaging extension ID.

- Bump browser-cli and extension version to 0.14.1 and cover the new behavior with pytest and extension packaging tests.

BREAKING CHANGE: cookies commands and the b.cookies SDK namespace have been removed; generic raw command execution now blocks non-safe commands unless explicitly allowed.

browser_cli/commands/watch.py

@@ -0,0 +1,60 @@
+from __future__ import annotations
+
+import json
+import time
+
+import click
+
+from browser_cli.commands import client_from_ctx, handle_errors
+
+@click.group("watch")
+def watch_group():
+    """Watch browser state and print changes."""
+
+@watch_group.command("tabs")
+@click.option("--interval", type=float, default=1.0, show_default=True)
+@click.option("--once", is_flag=True)
+@handle_errors
+def watch_tabs(interval, once):
+    """Watch the tab list as JSON snapshots."""
+    client = client_from_ctx()
+    previous = None
+    while True:
+        current = [t.__dict__ for t in client.tabs.list()]
+        if current != previous:
+            click.echo(json.dumps({"type": "tabs", "tabs": current}, default=str), flush=True)
+            previous = current
+        if once:
+            return
+        time.sleep(interval)
+
+@watch_group.command("page")
+@click.option("--field", default=None, help="Only print a single page.info field")
+@click.option("--interval", type=float, default=1.0, show_default=True)
+@handle_errors
+def watch_page(field, interval):
+    """Watch page.info for the active tab."""
+    client = client_from_ctx()
+    previous = object()
+    while True:
+        info = client.page.info()
+        current = info.get(field) if field else info
+        if current != previous:
+            click.echo(json.dumps({"type": "page", "field": field, "value": current}, default=str), flush=True)
+            previous = current
+        time.sleep(interval)
+
+@watch_group.command("dom")
+@click.argument("selector")
+@click.option("--interval", type=float, default=1.0, show_default=True)
+@handle_errors
+def watch_dom(selector, interval):
+    """Watch textContent for a selector."""
+    client = client_from_ctx()
+    previous = object()
+    while True:
+        current = client.dom.text(selector)
+        if current != previous:
+            click.echo(json.dumps({"type": "dom", "selector": selector, "text": current}, default=str), flush=True)
+            previous = current
+        time.sleep(interval)