fix(client): route /apps/* through /index.php for non-pretty-URL installs

Bare /apps/<app>/... URLs return 404 on Nextcloud installs without Pretty
URLs (URL rewriting), which is opt-in and not the default — see #732. The
/index.php/apps/... form is the universal entry point and works regardless
of web-server config, matching how /remote.php/dav and /ocs/v2.php already
have dedicated entry points.

Add a small _resolve_url helper on BaseNextcloudClient that rewrites
/apps/... → /index.php/apps/... at the top of _make_request, so every
current call site (notes, deck, cookbook, news) and any future ones are
covered transparently with no per-client churn.

Other path prefixes (/remote.php, /ocs, absolute URLs, already-prefixed
/index.php/apps) pass through unchanged. New unit tests in
tests/unit/client/test_base.py pin all six cases.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/unit/client/test_base.py

@@ -0,0 +1,70 @@
+"""Unit tests for BaseNextcloudClient.
+
+These cover the URL prefix logic that routes ``/apps/...`` calls through the
+universal ``/index.php`` entry point so the server works on Nextcloud installs
+without Pretty URLs (issue #732).
+"""
+
+import pytest
+
+from nextcloud_mcp_server.client.base import BaseNextcloudClient
+
+pytestmark = pytest.mark.unit
+
+
+def test_apps_path_is_prefixed_with_index_php():
+    """Bare ``/apps/<app>/...`` 404s on Nextcloud without Pretty URLs; the
+    universal ``/index.php/apps/...`` form must be used instead.
+    """
+    assert (
+        BaseNextcloudClient._resolve_url("/apps/notes/api/v1/notes")
+        == "/index.php/apps/notes/api/v1/notes"
+    )
+    assert (
+        BaseNextcloudClient._resolve_url("/apps/deck/api/v1.0/boards/1/stacks/2/cards")
+        == "/index.php/apps/deck/api/v1.0/boards/1/stacks/2/cards"
+    )
+
+
+def test_remote_php_dav_unchanged():
+    """WebDAV/CalDAV/CardDAV paths use a dedicated entry point and don't need
+    rewriting — leave them alone so we don't break the working call sites.
+    """
+    assert (
+        BaseNextcloudClient._resolve_url("/remote.php/dav/files/alice/foo.txt")
+        == "/remote.php/dav/files/alice/foo.txt"
+    )
+
+
+def test_ocs_path_unchanged():
+    """The ``ocs/v2.php`` prefix is also a dedicated entry point — no rewrite."""
+    assert (
+        BaseNextcloudClient._resolve_url("/ocs/v2.php/cloud/users")
+        == "/ocs/v2.php/cloud/users"
+    )
+
+
+def test_already_prefixed_unchanged():
+    """If a caller already passed ``/index.php/apps/...`` we must not double-prefix."""
+    assert (
+        BaseNextcloudClient._resolve_url("/index.php/apps/notes/api/v1/notes")
+        == "/index.php/apps/notes/api/v1/notes"
+    )
+
+
+def test_absolute_url_unchanged():
+    """Absolute URLs (full ``https://...``) are pass-through; only path-prefix
+    matching is intentional, and an ``http://...`` URL doesn't start with
+    ``/apps/``.
+    """
+    assert (
+        BaseNextcloudClient._resolve_url("https://cloud.example.org/apps/notes")
+        == "https://cloud.example.org/apps/notes"
+    )
+
+
+def test_empty_or_unrelated_paths_unchanged():
+    """Defensive cases: empty strings, root, and non-apps paths must pass through."""
+    assert BaseNextcloudClient._resolve_url("") == ""
+    assert BaseNextcloudClient._resolve_url("/") == "/"
+    assert BaseNextcloudClient._resolve_url("/status.php") == "/status.php"