DEVX-148: fix: add fallback URL for tea download

Co-authored-by: oblachno Admin <admin@oblachno.oblachno.fyi>

src/devx/tools/install_tools.py

@@ -70,6 +70,25 @@ def _download(url: str, dest: Path) -> None:
         shutil.copyfileobj(resp, f)
 
 
+def _download_with_fallback(urls: list[str], binary_name: str) -> Path:
+    """Try downloading a binary from a list of URLs, falling back on failure.
+
+    Returns the path to the installed binary. Raises if all URLs fail.
+    """
+    target_dir = _ensure_target_dir()
+    dest = target_dir / binary_name
+    errors: list[str] = []
+    for url in urls:
+        try:
+            _download(url, dest)
+            dest.chmod(0o755)
+            return dest
+        except Exception as exc:  # noqa: BLE001
+            errors.append(f"{url}: {exc}")
+            click.echo(f"  {binary_name}: retrying — {exc}")
+    raise click.ClickException(f"Failed to download {binary_name} from all URLs: {'; '.join(errors)}")
+
+
 def _download_and_extract_tarball(url: str, binary_name: str) -> Path:
     """Download a tarball, extract the binary, and install it to TARGET_DIR.
 
@@ -164,8 +183,13 @@ def install_tea() -> bool:
         click.echo("tea: already installed")
         return True
     arch = _arch()
-    url = f"https://dl.gitea.com/tea/{TEA_VERSION}/tea-{TEA_VERSION}-linux-{arch}"
-    dest = _download_binary(url, "tea")
+    # dl.gitea.com is the primary CDN, but it can return 403 from some networks.
+    # Fall back to the gitea.com release downloads URL.
+    urls = [
+        f"https://dl.gitea.com/tea/{TEA_VERSION}/tea-{TEA_VERSION}-linux-{arch}",
+        f"https://gitea.com/gitea/tea/releases/download/v{TEA_VERSION}/tea-{TEA_VERSION}-linux-{arch}",
+    ]
+    dest = _download_with_fallback(urls, "tea")
     click.echo(f"tea: installed to {dest}")
     return True