feat: group multi-browser output by source

- Add browser source grouping metadata to SDK-created tabs, groups,
  list results, and aggregate count results.
- Render grouped local/remote browser tables consistently for clients,
  tabs, groups, windows, sessions, and remote status output.
- Document remote control, auth, HTTP gateway usage, and the refreshed
  project structure in the README.
- Add coverage for grouped output and BrowserCounts browser_groups.
- Bump the Python package, extension manifest, and lockfile to 0.15.6.
- Add a just publish helper for building and publishing release artifacts.

browser_cli/commands/tabs.py

@@ -2,25 +2,22 @@ import base64
 import binascii
 import click
 from browser_cli.commands import client_from_ctx, gentle_mode_option, handle_errors, print_counts, tab_option
-from browser_cli.commands.rendering import build_tabs_tree, print_table_rows, print_tree
+from browser_cli.commands.rendering import build_tabs_tree, print_browser_grouped_table_rows, print_tree
 from rich.console import Console
 from rich.table import Table
 
 console = Console()
 
 def _print_tabs(tabs, *, show_browser: bool = False) -> None:
-  columns = []
-  if show_browser:
-    columns.append(("Browser", lambda tab: tab.browser or ""))
-  columns.extend([
+  columns = [
     ("ID", lambda tab: tab.id),
     ("Window", lambda tab: tab.window_id),
     ("Active", lambda tab: "[green]✓[/green]" if tab.active else ""),
     ("Muted", lambda tab: "[yellow]✓[/yellow]" if tab.muted else ""),
     ("Title", lambda tab: (tab.title or "")[:60]),
     ("URL", lambda tab: (tab.url or "")[:80]),
-  ])
-  print_table_rows(tabs, columns, console=console, empty_message="[yellow]No tabs found[/yellow]")
+  ]
+  print_browser_grouped_table_rows(tabs, columns, console=console, empty_message="[yellow]No tabs found[/yellow]")
 
 @click.group("tabs")
 def tabs_group():