feat(admin): document-vault limit fields on the admin surfaces

The two vault knobs become editable where operators already work: the
app-settings card gains the per-file upload cap (MB, 1-100, mirrors the
hard server ceiling) and the default per-account storage quota (GB,
commit-on-blur with clamped conversion to bytes); the user edit form
gains the per-user quota override (GB, empty = instance default). The
admin users list now carries the override so the form can show it.

Refs: document-vault plan W3-T7

src/components/admin/_shared.tsx

@@ -28,6 +28,9 @@ export interface AdminUser {
   createdAt: string;
   // v1.23 — per-user "require a second factor" override.
   mfaEnforced: boolean;
+  // Document vault — per-user storage-quota override in bytes; null means
+  // the instance-wide default applies.
+  documentQuotaBytes: number | null;
   passkeyCount: number;
 }
 
@@ -88,6 +91,11 @@ export interface AdminSettings {
   // v1.4.25 W7 — null means "fall back to Europe/Berlin in the resolver".
   defaultUserTimezone: string | null;
   moodLogGlobal?: boolean;
+  // Document vault — the two admin-tunable limits (bytes on the wire; the
+  // UI edits them as MB / GB). The per-file cap clamps to the hard 100 MiB
+  // ceiling server-side.
+  documentMaxFileBytes: number;
+  documentQuotaBytes: number;
 }
 
 export interface AdminAuditEntry {

src/components/admin/general-settings-section.tsx

@@ -1,14 +1,29 @@
 "use client";
 
-import { useMemo } from "react";
+import { useMemo, useState } from "react";
 import { Settings } from "lucide-react";
 import { SettingsCard } from "@/components/settings/settings-card";
 import { SettingsCardHeader } from "@/components/settings/_card-header";
 import { useTranslations } from "@/lib/i18n/context";
+import { Input } from "@/components/ui/input";
 import { NativeSelect } from "@/components/ui/native-select";
 import { SettingsToggle, useAdminSettings, useUpdateSettings } from "./_shared";
 import { listSupportedTimezones } from "@/lib/tz/format";
 
+// Document-vault limits: bytes on the wire, MB / GB in the UI. The bounds
+// mirror the server-side schema (per-file cap hard-clamped to 100 MiB —
+// single-shot GCM + bounded in-memory reads are load-bearing past that).
+const MIB = 1_048_576;
+const GIB = 1_073_741_824;
+const MAX_FILE_MB_MIN = 1;
+const MAX_FILE_MB_MAX = 100;
+const QUOTA_GB_MIN = 0.1;
+const QUOTA_GB_MAX = 1024;
+
+function clamp(value: number, min: number, max: number): number {
+  return Math.min(max, Math.max(min, value));
+}
+
 // v1.4.27 MB7 / CF-52 — the in-file `NATIVE_SELECT_CLASS` constant
 // retired; the shared `<NativeSelect>` primitive owns the visual
 // contract now. The admin copy previously diverged on the
@@ -26,6 +41,43 @@ export function GeneralSettingsSection() {
 
   const currentDefaultTz = settings?.defaultUserTimezone ?? "";
 
+  // Draft-while-editing pattern for the two limit inputs: null = not
+  // editing (show the stored value), string = the in-progress draft.
+  // Commit clamps to the schema bounds and converts to bytes.
+  const [maxFileDraft, setMaxFileDraft] = useState<string | null>(null);
+  const [quotaDraft, setQuotaDraft] = useState<string | null>(null);
+
+  const storedMaxFileMb =
+    settings?.documentMaxFileBytes != null
+      ? String(Math.round(settings.documentMaxFileBytes / MIB))
+      : "";
+  const storedQuotaGb =
+    settings?.documentQuotaBytes != null
+      ? String(Math.round((settings.documentQuotaBytes / GIB) * 10) / 10)
+      : "";
+
+  const commitMaxFile = () => {
+    if (maxFileDraft === null) return;
+    const parsed = Number(maxFileDraft);
+    setMaxFileDraft(null);
+    if (!Number.isFinite(parsed) || maxFileDraft.trim() === "") return;
+    const mb = clamp(Math.round(parsed), MAX_FILE_MB_MIN, MAX_FILE_MB_MAX);
+    const bytes = mb * MIB;
+    if (bytes === settings?.documentMaxFileBytes) return;
+    updateSettings.mutate({ documentMaxFileBytes: bytes });
+  };
+
+  const commitQuota = () => {
+    if (quotaDraft === null) return;
+    const parsed = Number(quotaDraft);
+    setQuotaDraft(null);
+    if (!Number.isFinite(parsed) || quotaDraft.trim() === "") return;
+    const gb = clamp(parsed, QUOTA_GB_MIN, QUOTA_GB_MAX);
+    const bytes = Math.round(gb * GIB);
+    if (bytes === settings?.documentQuotaBytes) return;
+    updateSettings.mutate({ documentQuotaBytes: bytes });
+  };
+
   return (
     <SettingsCard>
       <SettingsCardHeader
@@ -117,6 +169,65 @@ export function GeneralSettingsSection() {
             ))}
           </NativeSelect>
         </div>
+
+        {/* Document vault — the two admin-tunable limits (per-file cap +
+            per-user storage quota). Everything else about the vault is
+            committed behaviour; these are deliberately the only knobs. */}
+        <div className="flex flex-col gap-2 sm:flex-row sm:items-center sm:justify-between">
+          <div className="min-w-0">
+            <p className="text-sm font-medium">{t("admin.documentMaxFile")}</p>
+            <p className="text-muted-foreground text-xs">
+              {t("admin.documentMaxFileDescription")}
+            </p>
+          </div>
+          <div className="flex items-center gap-2 self-end sm:self-auto">
+            <Input
+              type="number"
+              inputMode="numeric"
+              min={MAX_FILE_MB_MIN}
+              max={MAX_FILE_MB_MAX}
+              step={1}
+              className="w-24 text-right tabular-nums"
+              aria-label={t("admin.documentMaxFile")}
+              value={maxFileDraft ?? storedMaxFileMb}
+              onChange={(e) => setMaxFileDraft(e.target.value)}
+              onBlur={commitMaxFile}
+              onKeyDown={(e) => {
+                if (e.key === "Enter") commitMaxFile();
+              }}
+              disabled={updateSettings.isPending || settings == null}
+            />
+            <span className="text-muted-foreground text-xs">MB</span>
+          </div>
+        </div>
+
+        <div className="flex flex-col gap-2 sm:flex-row sm:items-center sm:justify-between">
+          <div className="min-w-0">
+            <p className="text-sm font-medium">{t("admin.documentQuota")}</p>
+            <p className="text-muted-foreground text-xs">
+              {t("admin.documentQuotaDescription")}
+            </p>
+          </div>
+          <div className="flex items-center gap-2 self-end sm:self-auto">
+            <Input
+              type="number"
+              inputMode="decimal"
+              min={QUOTA_GB_MIN}
+              max={QUOTA_GB_MAX}
+              step={0.1}
+              className="w-24 text-right tabular-nums"
+              aria-label={t("admin.documentQuota")}
+              value={quotaDraft ?? storedQuotaGb}
+              onChange={(e) => setQuotaDraft(e.target.value)}
+              onBlur={commitQuota}
+              onKeyDown={(e) => {
+                if (e.key === "Enter") commitQuota();
+              }}
+              disabled={updateSettings.isPending || settings == null}
+            />
+            <span className="text-muted-foreground text-xs">GB</span>
+          </div>
+        </div>
       </div>
     </SettingsCard>
   );

src/components/admin/user-management-section.tsx

@@ -55,6 +55,9 @@ export function UserManagementSection() {
   const [editingUser, setEditingUser] = useState<AdminUser | null>(null);
   const [editUsername, setEditUsername] = useState("");
   const [editEmail, setEditEmail] = useState("");
+  // Document vault — per-user storage-quota override, edited in GB.
+  // Empty string = no override (the instance default applies).
+  const [editQuotaGb, setEditQuotaGb] = useState("");
   const [resetUser, setResetUser] = useState<AdminUser | null>(null);
   const [resetPassword, setResetPassword] = useState("");
   const [resetMsg, setResetMsg] = useState<string | null>(null);
@@ -142,6 +145,11 @@ export function UserManagementSection() {
     setEditingUser(u);
     setEditUsername(u.username);
     setEditEmail(u.email ?? "");
+    setEditQuotaGb(
+      u.documentQuotaBytes === null
+        ? ""
+        : String(Math.round((u.documentQuotaBytes / 1_073_741_824) * 10) / 10),
+    );
   }
 
   function startReset(u: AdminUser) {
@@ -448,11 +456,22 @@ export function UserManagementSection() {
             onSubmit={(e) => {
               e.preventDefault();
               if (updateUser.isPending) return;
+              const quotaTrimmed = editQuotaGb.trim();
+              const quotaParsed = Number(quotaTrimmed);
               updateUser.mutate({
                 id: editingUser.id,
                 data: {
                   username: editUsername,
                   email: editEmail || null,
+                  // Empty clears the override; a value clamps to the same
+                  // bounds the server schema enforces (0.1–1024 GB).
+                  documentQuotaBytes:
+                    quotaTrimmed === "" || !Number.isFinite(quotaParsed)
+                      ? null
+                      : Math.round(
+                          Math.min(1024, Math.max(0.1, quotaParsed)) *
+                            1_073_741_824,
+                        ),
                 },
               });
             }}
@@ -481,6 +500,32 @@ export function UserManagementSection() {
                 data-1p-ignore="true"
               />
             </div>
+            <div className="space-y-1">
+              <Label htmlFor="edit-document-quota">
+                {t("admin.userDocumentQuota")}
+              </Label>
+              <div className="flex items-center gap-2">
+                <Input
+                  id="edit-document-quota"
+                  type="number"
+                  inputMode="decimal"
+                  min={0.1}
+                  max={1024}
+                  step={0.1}
+                  className="w-28 text-right tabular-nums"
+                  value={editQuotaGb}
+                  onChange={(e) => setEditQuotaGb(e.target.value)}
+                  placeholder={t("admin.userDocumentQuotaDefault")}
+                  autoComplete="off"
+                  data-lpignore="true"
+                  data-1p-ignore="true"
+                />
+                <span className="text-muted-foreground text-xs">GB</span>
+              </div>
+              <p className="text-muted-foreground text-xs">
+                {t("admin.userDocumentQuotaHint")}
+              </p>
+            </div>
             <div className="flex gap-2">
               <Button
                 type="submit"