fix: ASCII-only install.ps1 comment; allow-list install_cli's uv PATH fallback

- install.ps1 must stay pure ASCII (PowerShell 5.1 ANSI code-page
  decoding, #66994/#67000): em-dash -> '--'
- tests/test_managed_runtime_resolution.py: install_cli()'s
  shutil.which('uv') is a reviewed fallback AFTER ensure_uv() misses

scripts/install.ps1

@@ -3183,7 +3183,7 @@ function Install-BrowserUseCli {
     $ErrorActionPreference = "Continue"
     try {
         # UV_TOOL_BIN_DIR keeps the binary inside Hermes' managed bin dir,
-        # where the browser tool resolves it — no reliance on the user PATH.
+        # where the browser tool resolves it -- no reliance on the user PATH.
         $env:UV_TOOL_BIN_DIR = $managedBin
         $env:UV_NO_CONFIG = "1"
         & $script:UvCmd tool install browser-use 2>&1 | Out-Null

tests/test_managed_runtime_resolution.py

@@ -74,6 +74,11 @@ _ALLOWED: dict[tuple[str, str], str] = {
         "Fallback after resolve_uv(), plus the except-branch for the "
         "hermes_cli import guard."
     ),
+    ("tools/browser_use_cli.py", "uv"): (
+        "install_cli()'s fallback after ensure_uv() misses — a user-installed "
+        "uv on PATH is a legitimate last rung before giving up with install "
+        "guidance."
+    ),
     ("hermes_cli/gateway.py", "node"): (
         "Fallback rung of _append_node_dir_for_service(), after the managed "
         "dirs from iter_hermes_node_dirs() are already appended."