feat(lanes): show Add Lane auto-setup summary before closing modal

The three setup calls (profile/agents/mcp) fired after worktree
creation but their outcome was only logged to the console. Keep the
modal open with a ✓/✗ summary for a few seconds (or until dismissed)
so the user actually sees what happened, matching the original F5 design.

docs/LANES.md

@@ -32,7 +32,7 @@ ccam lanes add --repo /path/to/repo --title "My Feature" --base main --slug my-f
 
 `--title`, `--base`, and `--slug` are optional. The CLI waits for background provisioning to finish and reports either the ready lane or its failure notes.
 
-Adding a lane through the dashboard's "+ Add lane" flow also auto-runs, best-effort, in parallel: `ccam lanes profile init` (only if a Node.js project is detected — most repos won't be, and that's a normal outcome, not a failure), `ccam lanes agents install`, and `ccam lanes mcp sync`. None of the three blocks the lane from being created or from each other — a lane whose repo has no MCP servers configured, for instance, still gets created and is still usable, just without a synced `.mcp.json`. Run any of the three manually later (from the lane's own card, or the CLI) if the automatic attempt didn't apply.
+Adding a lane through the dashboard's "+ Add lane" flow also auto-runs, best-effort, in parallel: `ccam lanes profile init` (only if a Node.js project is detected — most repos won't be, and that's a normal outcome, not a failure), `ccam lanes agents install`, and `ccam lanes mcp sync`. None of the three blocks the lane from being created or from each other — a lane whose repo has no MCP servers configured, for instance, still gets created and is still usable, just without a synced `.mcp.json`. The modal shows a ✓/✗ summary of the three results for a few seconds (or until dismissed) before closing. Run any of the three manually later (from the lane's own card, or the CLI) if the automatic attempt didn't apply.
 
 ## Destructive lane actions