fix(wrap): show the dashboard URL when the proxy is already running (#1313)

## Description

I was running `headroom wrap claude` and could not find the dashboard
URL anywhere. I eventually spotted it in the README demo gif. The reason
is that `_ensure_proxy` only echoes the URL on the path that starts or
restarts the proxy. Once a proxy is already up, the function prints
`Proxy already running on port {port}` and returns, with no URL. That
early-return path is the common case: every wrap after the first one
hits it, so in practice the dashboard URL is almost never shown.

This adds the same `Dashboard: http://127.0.0.1:{port}/dashboard` line
to the two already-running branches (the inline one and the
persistent-deployment one), so the URL shows up every time, not just on
a cold start.

Closes # N/A (no tracking issue)

## Type of Change

- [x] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)

## Changes Made

- `headroom/cli/wrap.py`: echo the dashboard URL in both "proxy already
running" branches of `_ensure_proxy`, matching the line the
start/restart path already prints.
- `tests/test_cli/test_wrap_helpers.py`: new test that drives
`_ensure_proxy` down the already-running path and asserts the dashboard
URL is in the output.

## Testing

- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check`)
- [x] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [x] Manual testing performed

### Test Output

```text
$ uv run --extra dev python -m pytest tests/test_cli/test_wrap_helpers.py -q
40 passed in 0.20s

$ uv run --extra dev ruff check headroom/cli/wrap.py tests/test_cli/test_wrap_helpers.py
All checks passed!

$ uv run --extra dev mypy headroom/cli/wrap.py
Success: no issues found in 1 source file
```

## Real Behavior Proof

- Environment: macOS, Python 3.13, this branch, `headroom wrap claude`
against an already-running proxy on port 8787.
- Exact command / steps: run `claude` (aliased to `headroom wrap
claude`) a second time, so the proxy is already up and `_ensure_proxy`
takes the early-return path.
- Observed result: before this change the output stopped at `Proxy
already running on port 8787` with no URL. After it, the next line is
`Dashboard: http://127.0.0.1:8787/dashboard`. The new unit test pins
this by mocking a healthy running proxy and asserting the URL is
printed.
- Not tested: I did not open the rendered dashboard in a browser as part
of this change. The fix is purely the printed line, which the unit test
covers.

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable

## Additional Notes

I scoped this to the print line plus its test on purpose. ruff and mypy
are clean on the files I touched. I left the CHANGELOG checkbox
unchecked because this is a one-line user-facing string fix with no
behavior change beyond the extra output, but I am happy to add a
CHANGELOG entry if you would like one. The same for docs, I don't think
it's needed to have one about this

headroom/cli/wrap.py

@@ -2406,6 +2406,7 @@ def _ensure_proxy(
                         f"is running stale Headroom {running_version} and could not be restarted."
                     )
                 click.echo(f"  Proxy already running on port {port}")
+                click.echo(f"  Dashboard:    http://127.0.0.1:{port}/dashboard")
                 return None
             if helpers._recover_persistent_proxy(port):
                 return None
@@ -2536,6 +2537,7 @@ def _ensure_proxy(
 
             if not needs_restart:
                 click.echo(f"  Proxy already running on port {port}")
+                click.echo(f"  Dashboard:    http://127.0.0.1:{port}/dashboard")
                 return None
 
         # Start (or restart) the proxy with the requested flags

tests/test_cli/test_wrap_helpers.py

@@ -739,3 +739,29 @@ class TestProxyClientRefCounting:
 
         # Second unregister is a no-op, not an error.
         wrap_mod._unregister_proxy_client(self.PORT)
+
+
+# ---------------------------------------------------------------------------
+# _ensure_proxy — dashboard URL is surfaced even when the proxy is already up.
+# ---------------------------------------------------------------------------
+
+
+def test_ensure_proxy_already_running_prints_dashboard_url(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """When a healthy proxy is already running, the dashboard URL is printed.
+
+    Regression: the URL was only echoed on the start/restart path, so repeat
+    wraps (the common case) never told the user where the dashboard lives.
+    """
+    port = 1234
+    monkeypatch.setattr(wrap_mod, "_find_persistent_manifest", lambda _p: None)
+    monkeypatch.setattr(wrap_mod, "_check_proxy", lambda _p: True)
+    monkeypatch.setattr(wrap_mod, "_query_proxy_health", lambda _p: {})
+    monkeypatch.setattr(wrap_mod, "_proxy_needs_version_restart", lambda _h: False)
+    monkeypatch.setattr(wrap_mod, "_proxy_health_config", lambda _h: None)
+    monkeypatch.setattr(wrap_mod, "_query_proxy_config", lambda _p: None)
+
+    output = _run_in_click_context(lambda: wrap_mod._ensure_proxy(port, no_proxy=False))
+
+    assert f"http://127.0.0.1:{port}/dashboard" in output