docs(tasks): v3.3.94 measurement build + confirmed localization (renderer innocent, lag from active uploads/oversubscription)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tasks/todo.md

@@ -1,3 +1,38 @@
+# v3.3.94 — comprehensive measurement build (user: "mach alles messen was man messen kann")
+
+Localization so far (each step EMPIRICAL, not by elimination — advisor caught the elimination-leap):
+- Renderer queue render PROVEN cheap: loaded the REAL app.js in headless Chromium (Playwright) with a mocked
+  window.api, populated Q=1000 / 61 active / progress sort, drove the real onUploadProgressBatch +
+  renderQueueTable + scroll → ALL <0.5ms. (Caveat: component cost, not frame rate.)
+- User CONFIRMED the discriminator: a full 1000-row queue scrolls SMOOTH when idle, ruckelt ONLY while ~61–70
+  uploads are active → the lag is driven by the active uploads (main-process / system load), not the table.
+- Screenshot: 70 connections, 1413 files, 41.3 MB/s, "write ECONNRESET". ECONNRESET is already classified
+  transient (upload-manager _isTransientNetworkError line 171 → retried, not account-fatal) — it's the
+  SIGNATURE of oversubscription (servers RST the excess connections). Same root cause as the lag.
+
+Immediate user lever (already exists): Settings → Uploads → "Globale parallele Uploads" (parallelUploadCount,
+global semaphore, default 0=off). Capping total concurrent uploads (~20) should fix lag AND ECONNRESET AND
+likely keep throughput (bandwidth-limited at 41 MB/s; reset connections waste bandwidth on retries).
+
+SHIPPED measurement (all additive, zero upload-behavior change) to pinpoint CPU-vs-IO vs renderer from the
+user's REAL 70-connection run:
+- main.js ELD line now also logs: cpu=X%core (process.cpuUsage delta / wall, >100% = multi-core),
+  rss=YMB, active-by-hoster={dood:.., voe:.., ...} (per-hoster live connection distribution → shows which
+  hoster is oversubscribed), transient-errs=N (cumulative ECONNRESET-class on the primary path), pending=M.
+- lib/upload-manager.js: getDiagnostics() {activeByHoster, transientErrors, pending, active}; activeEntry
+  now carries hoster; _transientErrorTotal++ in the primary catch when _isTransientNetworkError.
+- renderer/app.js: PerformanceObserver('longtask') + a rAF frame-time monitor → logs every 5s WHILE
+  uploading: `renderer-perf active=N fps=X jankFrames=Y worstFrame=Zms longtasks=W maxTask=Vms`. This is the
+  DIRECT renderer ground truth (the component-timing harness couldn't capture real frame rate). Low fps /
+  high jankFrames / longtasks → renderer IS blocked; ~60fps + no jank while it still feels laggy → it's the
+  main-process/system, and the cpu=/eld= numbers in the same log say CPU-bound (→ workers/cap) vs IO-bound.
+Both logs land in the normal debug log (logInfo / window.api.debugLog). 397/397 tests, eslint clean.
+
+NEXT: user runs the 70-load on v3.3.94, shares the `eventloop-delay` + `renderer-perf` log lines (or connects
+diagnostics). Those two lines together localize it definitively. Do NOT build workers/cap before that.
+
+---
+
 # v3.3.93 — THE renderer lag knot FOUND + FIXED + MEASURED: formatDateTime per progress event
 
 User gave the decisive data: "25 connections okay, 50+61 laggt, EVTL wenn die uploadenden Zeilen nicht im