feat(dashboard): add corpus dashboard at /dashboard/

Full private corpus dashboard for tools.dobetternorge.no users — each SSO
account gets an auto-provisioned CaveauAI tenant (clients row, corpus) on
first visit. Includes upload (file/paste/URL), RAG chat with SSE streaming
and citation chips, document CRUD, FalkorDB graph relations tab, and
improved save-from-tool flow with tag/preview support.

- dashboard/{index,documents,document,upload,chat,settings}.php
- api/dashboard/{corpus-init,documents,upload,ingest-status,chat-stream,
  save-from-tool,graph}.php
- includes/{CorpusProvision,layout_dashboard,layout_dashboard_footer}.php
- assets/css/dashboard.css  assets/js/corpus-save.js (routing upgrade)
- includes/{bootstrap,layout}.php extended for dashboard provisioning

Migration 141 (clients.dbn_sso_uid + import_method enum) applied on chloe.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

api/dashboard/ingest-status.php

@@ -0,0 +1,53 @@
+<?php
+/**
+ * GET /api/dashboard/ingest-status.php?ids=1,2,3
+ *
+ * Returns per-doc status for polling during URL ingest (background) or to
+ * surface error messages after a failed sync upload.
+ *
+ * Response:
+ *   { ok, statuses: [ {id, status, chunk_count, error_message}, ... ] }
+ */
+
+declare(strict_types=1);
+
+require_once dirname(__DIR__, 2) . '/includes/bootstrap.php';
+
+dbnToolsRequireMethod('GET');
+dbnToolsRequireAuth();
+
+try {
+    $tenant = dbnToolsEnsureDashboardTenant();
+} catch (DbnToolsHttpException $e) {
+    dbnToolsError($e->getMessage(), $e->status, $e->errorCode);
+}
+$clientId = (int)$tenant['client_id'];
+
+$raw = (string)($_GET['ids'] ?? '');
+$ids = array_values(array_filter(
+    array_map('intval', explode(',', $raw)),
+    fn($v) => $v > 0
+));
+if (!$ids) {
+    dbnToolsRespond(['ok' => true, 'statuses' => []]);
+}
+$ids = array_slice($ids, 0, 100);
+
+$db = dbnToolsDb();
+$placeholders = implode(',', array_fill(0, count($ids), '?'));
+$sql = "SELECT id, status, chunk_count, error_message
+        FROM client_documents
+        WHERE client_id = ? AND id IN ({$placeholders})";
+$stmt = $db->prepare($sql);
+$stmt->execute(array_merge([$clientId], $ids));
+$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
+
+dbnToolsRespond([
+    'ok'       => true,
+    'statuses' => array_map(fn($r) => [
+        'id'            => (int)$r['id'],
+        'status'        => (string)$r['status'],
+        'chunk_count'   => (int)$r['chunk_count'],
+        'error_message' => $r['error_message'] ?? null,
+    ], $rows),
+]);