feat(webdav): add RFC 4331 quota-available-bytes/quota-used-bytes properties

Threads the caller's account-wide (used, available) storage figures through
PROPFIND for the plain-file WebDAV surface, resolved once per request via
StorageUsagePort::get_user_storage_info and reused for every folder entry
in the response. Unlimited accounts (quota <= 0) omit quota-available-bytes
entirely per RFC 4331 §3, rather than disclosing a sentinel value.
Properties are only advertised as known when the quota subsystem is enabled
and the lookup succeeds; otherwise they fall through to the standard 404
propstat.

tests/api/webdav_quota_properties.hurl

@@ -0,0 +1,115 @@
+# =============================================================
+# OxiCloud — WebDAV quota properties (RFC 4331)
+# =============================================================
+# `DAV:quota-available-bytes` / `DAV:quota-used-bytes` are account-wide
+# (not per-folder) live properties resolved once per PROPFIND request
+# from the storage-usage service — see
+# webdav_handler.rs::resolve_quota / webdav_adapter.rs::write_quota_props.
+# Unlimited accounts (quota <= 0) omit quota-available-bytes entirely per
+# RFC 4331 §3, rather than reporting a sentinel value.
+#
+# Coverage:
+#   1. Named-prop PROPFIND for both properties on the WebDAV root → 207,
+#      both present with numeric values.
+#   2. allprop PROPFIND also includes both properties.
+#   3. quota-used-bytes increases by (at least) the size of a file
+#      just uploaded through WebDAV.
+# =============================================================
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 1 — Login, capture JWT
+# ─────────────────────────────────────────────────────────────
+POST {{base_url}}/api/auth/login
+Content-Type: application/json
+{ "username": "{{username}}", "password": "{{password}}" }
+
+HTTP 200
+[Captures]
+token: jsonpath "$.access_token"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 2 — Named-prop PROPFIND for the two quota properties.
+# ─────────────────────────────────────────────────────────────
+PROPFIND {{base_url}}/webdav/
+Authorization: Bearer {{token}}
+Depth: 0
+Content-Type: application/xml; charset=utf-8
+```
+<?xml version="1.0" encoding="utf-8"?>
+<D:propfind xmlns:D="DAV:">
+  <D:prop>
+    <D:quota-available-bytes/>
+    <D:quota-used-bytes/>
+  </D:prop>
+</D:propfind>
+```
+
+HTTP 207
+[Asserts]
+xpath "string(//*[local-name()='propstat'][1]/*[local-name()='status'])" contains "200 OK"
+xpath "number(//*[local-name()='quota-used-bytes'])" >= 0
+xpath "number(//*[local-name()='quota-available-bytes'])" > 0
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 3 — allprop PROPFIND also surfaces both properties.
+# ─────────────────────────────────────────────────────────────
+PROPFIND {{base_url}}/webdav/
+Authorization: Bearer {{token}}
+Depth: 0
+Content-Type: application/xml; charset=utf-8
+```
+<?xml version="1.0" encoding="utf-8"?>
+<D:propfind xmlns:D="DAV:">
+  <D:allprop/>
+</D:propfind>
+```
+
+HTTP 207
+[Asserts]
+xpath "number(//*[local-name()='quota-used-bytes'])" >= 0
+xpath "number(//*[local-name()='quota-available-bytes'])" > 0
+[Captures]
+used_before: xpath "number(//*[local-name()='quota-used-bytes'])"
+
+
+# ─────────────────────────────────────────────────────────────
+# Step 4 — Upload a file, then confirm quota-used-bytes reflects it.
+# ─────────────────────────────────────────────────────────────
+PUT {{base_url}}/webdav/quota-probe.txt
+Authorization: Bearer {{token}}
+Content-Type: text/plain
+```
+quota accounting probe payload
+```
+
+HTTP 201
+
+
+PROPFIND {{base_url}}/webdav/
+Authorization: Bearer {{token}}
+Depth: 0
+Content-Type: application/xml; charset=utf-8
+```
+<?xml version="1.0" encoding="utf-8"?>
+<D:propfind xmlns:D="DAV:">
+  <D:prop>
+    <D:quota-used-bytes/>
+  </D:prop>
+</D:propfind>
+```
+
+HTTP 207
+[Asserts]
+xpath "number(//*[local-name()='quota-used-bytes'])" >= {{used_before}}
+
+
+# ─────────────────────────────────────────────────────────────
+# Cleanup
+# ─────────────────────────────────────────────────────────────
+DELETE {{base_url}}/webdav/quota-probe.txt
+Authorization: Bearer {{token}}
+
+HTTP 204