fix: locate uv binary before upgrade to handle non-standard PATH

When running as root or via sudo, /root/.local/bin may not be in PATH.
Use shutil.which with fallback to ~/.local/bin/uv, and fail clearly
if uv can't be found.

hate_crack/main.py

@@ -831,11 +831,23 @@ def _run_upgrade():
         )
         raise SystemExit(1)
     repo_root = git_root_result.stdout.strip()
+
+    # Locate the uv binary. It may not be in PATH when running as root or via sudo.
+    import shutil
+
+    uv = shutil.which("uv") or os.path.expanduser("~/.local/bin/uv")
+    if not os.path.isfile(uv):
+        print(
+            "\n  Could not find the uv binary."
+            "\n  Run manually: git pull && git fetch --tags && uv sync --reinstall-package hate_crack\n"
+        )
+        raise SystemExit(1)
+
     result = subprocess.run(
         # git fetch --tags ensures new release tags are visible to setuptools-scm.
         # uv sync --reinstall-package forces hate_crack to be rebuilt from
         # current source so setuptools-scm generates the correct version.
-        "git pull && git fetch --tags && uv sync --reinstall-package hate_crack",
+        f"git pull && git fetch --tags && {uv} sync --reinstall-package hate_crack",
         shell=True,
         cwd=repo_root,
     )

tests/test_version_check.py

@@ -151,7 +151,9 @@ class TestCheckForUpdates:
             hc_module, "REQUESTS_AVAILABLE", True
         ), patch("builtins.input", return_value="y"), patch(
             "subprocess.run", side_effect=[git_root_proc, make_proc]
-        ) as mock_run, pytest.raises(
+        ) as mock_run, patch("shutil.which", return_value="/usr/local/bin/uv"), patch(
+            "os.path.isfile", return_value=True
+        ), pytest.raises(
             SystemExit
         ):
             mock_requests.get.return_value = mock_resp
@@ -181,6 +183,8 @@ class TestCheckForUpdates:
             hc_module, "REQUESTS_AVAILABLE", True
         ), patch("builtins.input", return_value="y"), patch(
             "subprocess.run", side_effect=[git_root_proc, make_proc]
+        ), patch("shutil.which", return_value="/usr/local/bin/uv"), patch(
+            "os.path.isfile", return_value=True
         ), pytest.raises(
             SystemExit
         ):
@@ -216,6 +220,14 @@ class TestCheckForUpdates:
 class TestRunUpgrade:
     """Tests for _run_upgrade() called directly via --update flag."""
 
+    @pytest.fixture(autouse=True)
+    def mock_uv(self):
+        """Patch shutil.which and os.path.isfile so uv is always 'found'."""
+        with patch("shutil.which", return_value="/usr/local/bin/uv"), patch(
+            "os.path.isfile", return_value=True
+        ):
+            yield
+
     def test_run_upgrade_success(self, hc_module, capsys):
         git_root_proc = MagicMock()
         git_root_proc.returncode = 0
@@ -263,6 +275,20 @@ class TestRunUpgrade:
         output = capsys.readouterr().out
         assert "Run manually" in output
 
+    def test_run_upgrade_uv_not_found(self, hc_module, capsys):
+        git_root_proc = MagicMock()
+        git_root_proc.returncode = 0
+        git_root_proc.stdout = "/fake/repo\n"
+
+        with patch("subprocess.run", return_value=git_root_proc), patch(
+            "shutil.which", return_value=None
+        ), patch("os.path.isfile", return_value=False), pytest.raises(SystemExit) as exc:
+            hc_module._run_upgrade()
+
+        assert exc.value.code == 1
+        output = capsys.readouterr().out
+        assert "uv binary" in output
+
     def test_upgrade_prompt_ctrl_c_continues(self, hc_module, capsys):
         mock_resp = MagicMock()
         mock_resp.json.return_value = {"tag_name": "v99.0.0"}