style: repo-wide lint pass — make the lint gate green again

Push builds have been RED on the lint step since ~build 209 from accumulated
formatting drift. This is the mechanical cleanup: ruff format + ruff --fix
(UP038 isinstance unions, SIM105 contextlib.suppress, UP031 f-strings, SIM115
tempfile context manager), shfmt -i 2 -ci, nixpkgs-fmt/statix/deadnix (merged
attrsets, dropped unused lib args), yamllint, and shell quoting fixes in
tests/lasuite-docs/setup_custom_tests.sh. No behaviour changes intended;
lint: PASS, unit tests: 138 passed.

tests/cryptpad/playwright/test_pad_create.py

@@ -51,9 +51,9 @@ def test_cryptpad_spa_renders_with_no_console_errors(live_app):
             title = (page.title() or "").lower()
             body = page.content()
             blower = body.lower()
-            assert "cryptpad" in title or "cryptpad" in blower, (
-                f"CryptPad SPA does not carry brand. title={title!r}, body excerpt: {body[:200]!r}"
-            )
+            assert (
+                "cryptpad" in title or "cryptpad" in blower
+            ), f"CryptPad SPA does not carry brand. title={title!r}, body excerpt: {body[:200]!r}"
 
             # Canonical CryptPad asset references in the rendered DOM
             canonical = ("/customize/", "/components/", "main.js", "/api/broadcast")