v3.8.2 — *arr Cleanup End-to-End & Completion-Flag Accuracy

🐛 Fixed

• Downloads marked complete at 99.995% of bytes received. Every normalizer was running progress through parseFloat((x).toFixed(2)) for display, and the unified item builder then used that rounded value (progress >= 100) as the completion oracle. JavaScript's .toFixed(2) rounds half-away-from-zero, so e.g. a 100GB aMule file with 5MB still missing (99.9952%) got flipped to complete=true — premature pausedUP state in the qBit-compat layer, premature shared-vs-active routing in delete/pause handlers. Completion is now sourced per-client from authoritative signals: aMule from bytes-equality on EC_TAG_PARTFILE_SIZE_DONE (verified parts only), rTorrent from d.complete=, qBittorrent from raw progress >= 1.0, Deluge from raw progress >= 100, Transmission from percentDone >= 1.0. Display progress stays at 2-decimal precision; only the completion flag changed.
• Transmission downloaded counter could exceed total size on poisoned torrents — the field was being shipped from downloadedEver, which Transmission's docs explicitly warn "can grow very large" since it includes redundant re-fetches of corrupt data. Now haveValid + haveUnchecked (bytes actually on disk).
• Sonarr/Radarr never called torrents/delete after import even after the v3.8.1 pausedUP state fix. Tracing Radarr's QBittorrent.cs:240: CanBeRemoved requires three conjuncts — RemoveCompletedDownloads, state ∈ {pausedUP, stoppedUP}, AND HasReachedSeedLimit. We were emitting ratio_limit: -2 (= "use global config"), which only resolves to true if the user has MaxRatioEnabled in qBit's preferences. The compat layer now emits ratio_limit: 0, real ratio / uploaded / upspeed values from EC_TAG_KNOWNFILE_XFERRED_ALL, so all three conjuncts are satisfied at completion and *arr cleanup fires (#42).
• /api/v2/torrents/info returned [] intermittently when no WebSocket clients were connected — autoRefreshManager skips getBatchData() entirely when no WS clients are connected (the WS-or-history-due gate), so the cache aged out past the qBit-compat handler's 10s freshness window and the handler shipped empty arrays. The handler now uses a new DataFetchService.getOrFetchBatchData() that fetches on cache miss; getBatchData() itself is coalesced — concurrent callers (autoRefresh loop + Sonarr/Radarr/Prowlarr polls) share one in-flight fetch instead of triggering parallel client queries (#42).