feat(indexing): Lot 4 - Progression temps reel, Full Rebuild, Optimisations

- Ajout migrations DB: index_job_errors, library_monitoring, full_rebuild_type
- API: endpoints progression temps reel (/jobs/:id/stream), active jobs, details
- API: support full_rebuild avec suppression donnees existantes
- Indexer: logs detailles avec timing [SCAN][META][PARSER][BDD]
- Indexer: optimisation parsing PDF (lopdf -> pdfinfo) 235x plus rapide
- Indexer: corrections chemins LIBRARIES_ROOT_PATH pour dev local
- Backoffice: composants JobProgress, JobsIndicator (header), JobsList
- Backoffice: SSE streaming pour progression temps reel
- Backoffice: boutons Index/Index Full sur page libraries
- Backoffice: highlight job apres creation avec redirection
- Fix: parsing volume type i32, sync meilisearch cleanup

Perf: parsing PDF passe de 8.7s a 37ms
Perf: indexation 45 fichiers en ~15s vs plusieurs minutes avant

apps/backoffice/app/components/JobsIndicator.tsx

@@ -0,0 +1,144 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import Link from "next/link";
+
+interface Job {
+  id: string;
+  status: string;
+  current_file: string | null;
+  progress_percent: number | null;
+}
+
+interface JobsIndicatorProps {
+  apiBaseUrl: string;
+  apiToken: string;
+}
+
+export function JobsIndicator({ apiBaseUrl, apiToken }: JobsIndicatorProps) {
+  const [activeJobs, setActiveJobs] = useState<Job[]>([]);
+  const [isOpen, setIsOpen] = useState(false);
+
+  useEffect(() => {
+    const fetchActiveJobs = async () => {
+      try {
+        const response = await fetch(`${apiBaseUrl}/index/jobs/active`, {
+          headers: {
+            "Authorization": `Bearer ${apiToken}`,
+          },
+        });
+
+        if (response.ok) {
+          const jobs = await response.json();
+          // Enrich with details for running jobs
+          const jobsWithDetails = await Promise.all(
+            jobs.map(async (job: Job) => {
+              if (job.status === "running") {
+                try {
+                  const detailRes = await fetch(`${apiBaseUrl}/index/jobs/${job.id}`, {
+                    headers: { "Authorization": `Bearer ${apiToken}` },
+                  });
+                  if (detailRes.ok) {
+                    const detail = await detailRes.json();
+                    return { ...job, ...detail };
+                  }
+                } catch {
+                  // ignore detail fetch errors
+                }
+              }
+              return job;
+            })
+          );
+          setActiveJobs(jobsWithDetails);
+        }
+      } catch {
+        // Silently fail
+      }
+    };
+
+    fetchActiveJobs();
+    const interval = setInterval(fetchActiveJobs, 5000);
+
+    return () => clearInterval(interval);
+  }, [apiBaseUrl, apiToken]);
+
+  const pendingCount = activeJobs.filter(j => j.status === "pending").length;
+  const runningCount = activeJobs.filter(j => j.status === "running").length;
+  const totalCount = activeJobs.length;
+
+  if (totalCount === 0) {
+    return (
+      <Link href="/jobs" className="jobs-indicator empty">
+        <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
+          <rect x="4" y="4" width="16" height="16" rx="2" />
+          <path d="M8 12h8M12 8v8" />
+        </svg>
+      </Link>
+    );
+  }
+
+  return (
+    <div className="jobs-indicator-container">
+      <button 
+        className="jobs-indicator active" 
+        onClick={() => setIsOpen(!isOpen)}
+        title={`${totalCount} active job${totalCount !== 1 ? 's' : ''}`}
+      >
+        <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
+          <rect x="4" y="4" width="16" height="16" rx="2" />
+          <path d="M8 12h8M12 8v8" />
+        </svg>
+        {totalCount > 0 && (
+          <span className="jobs-badge">
+            {totalCount > 9 ? "9+" : totalCount}
+          </span>
+        )}
+        {runningCount > 0 && (
+          <span className="jobs-pulse" />
+        )}
+      </button>
+
+      {isOpen && (
+        <div className="jobs-dropdown">
+          <div className="jobs-dropdown-header">
+            <strong>Active Jobs</strong>
+            <Link href="/jobs" onClick={() => setIsOpen(false)}>View all</Link>
+          </div>
+          
+          {activeJobs.length === 0 ? (
+            <p className="jobs-empty">No active jobs</p>
+          ) : (
+            <ul className="jobs-list">
+              {activeJobs.map(job => (
+                <li key={job.id} className={`job-item job-${job.status}`}>
+                  <div className="job-header">
+                    <span className={`job-status status-${job.status}`}>
+                      {job.status}
+                    </span>
+                    <code className="job-id">{job.id.slice(0, 8)}</code>
+                  </div>
+                  {job.status === "running" && job.progress_percent !== null && (
+                    <div className="job-mini-progress">
+                      <div 
+                        className="job-progress-bar" 
+                        style={{ width: `${job.progress_percent}%` }}
+                      />
+                      <span>{job.progress_percent}%</span>
+                    </div>
+                  )}
+                  {job.current_file && (
+                    <p className="job-file" title={job.current_file}>
+                      {job.current_file.length > 30 
+                        ? job.current_file.substring(0, 30) + "..." 
+                        : job.current_file}
+                    </p>
+                  )}
+                </li>
+              ))}
+            </ul>
+          )}
+        </div>
+      )}
+    </div>
+  );
+}