RELEASE_NOTES_0.7.4.md

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+# WhispAssist v0.7.4
+
+**Privacy-first, Windows-native meeting assistant — everything on-device, nothing leaves unless you say so.**
+
+A small, focused performance release for **CPU transcription**. If WhispAssist runs the Whisper
+engine on your CPU — either because your machine has no usable GPU/NPU, or because you selected
+the CPU backend — this update takes it from far-slower-than-real-time to comfortably real-time.
+Machines on the NPU or GPU backends are unaffected in behavior and simply pick up a
+better-optimized build. Nothing here changes the privacy posture; there are no new downloads.
+
+One universal installer (**MSI** and **NSIS**) covers every machine: **Vulkan** for all GPUs
+(NVIDIA/AMD/Intel), the Intel **NPU** (OpenVINO), a **DirectML** fallback, and **CPU**.
+
+---
+
+## ⚡ CPU transcription fixed (up to ~90× faster on hybrid Intel CPUs)
+
+Whisper-on-CPU previously spawned one worker thread per logical CPU. On modern hybrid Intel
+processors (P-cores + E-cores + low-power E-cores) the workers synchronize in lock-step, so the
+two slow low-power cores stalled *every* step while the remaining threads burned CPU waiting —
+transcription ran ~20× slower than real time while looking like it was using the whole machine.
+
+WhispAssist now caps Whisper's CPU decode at **4 threads** (the whisper.cpp upstream default).
+Measured on a Core Ultra 5 135U over a 4-minute test corpus, same accuracy:
+
+| | before | after |
+|---|---|---|
+| Speed vs real time | 20× **slower** | **4.6× faster** (RTF 0.218) |
+| CPU cost per second of audio | 232.6 cpu-sec | 0.83 cpu-sec |
+
+Live (streaming) transcription shares this code path and benefits equally. If you want to
+experiment, the `WA_WHISPER_THREADS` environment variable overrides the cap.
+
+## 🔧 Native code now built fully optimized
+
+A build-toolchain issue caused the bundled native libraries (including whisper.cpp's CPU
+kernels) to be compiled **without compiler optimization**. That's fixed; this release ships
+optimized native code across the board. (For CPU transcription the thread fix above is the
+dominant win; this one is belt-and-suspenders for everything else.)
+
+---
+
+## 📦 Install
+
+**Requirements:** Windows 10 or 11 (x64). WhispAssist needs **WebView2** (preinstalled on Windows 11;
+the installer fetches it on Windows 10). Importing from a file/URL additionally needs **`ffmpeg`**
+(and **`yt-dlp`** for URLs) on your PATH — the Import dialog links to both.
+
+1. Download **`WhispAssist_0.7.4_x64_en-US.msi`** (or the NSIS **`WhispAssist_0.7.4_x64-setup.exe`**).
+2. Run it and accept the UAC prompt. If SmartScreen appears, choose **More info → Run anyway**.
+3. Launch **WhispAssist** from the Start menu.
+
+On first run WA picks the best transcription backend (**NPU → NVIDIA → AMD → Intel → CPU**). It runs
+without admin rights, does **not** add itself to startup unless you opt in, and keeps all data under
+`%LOCALAPPDATA%\WhispAssist`.
+
+Deploying to many machines? See [`docs/enterprise-deployment.md`](docs/enterprise-deployment.md).
+
+## 🔐 Checksums (SHA-256)
+
+```
+5c4e6d6b23a4b404c6fa200b6491e74f143c3a886042dc3bef3c2861168ef17c  WhispAssist_0.7.4_x64_en-US.msi
+eb2ececff06373e9cbb43ee6455c433c1b88785e9060b68ef7bed193191d9761  WhispAssist_0.7.4_x64-setup.exe
+```
+
+Verify after download:
+
+```powershell
+Get-FileHash .\WhispAssist_0.7.4_x64_en-US.msi -Algorithm SHA256
+```
+
+---
+
+## Privacy, unchanged
+Everything optional is **off by default**. With nothing configured, WhispAssist makes **no content
+egress at all**. Recording is opt-in; sync/AI credentials live only in the OS credential store; the
+MCP server is loopback-only and adds no egress; the deployment file never carries secrets. The
+reachable-host allowlist is derived from your settings and enforced in the core.