Initial commit: InstaLPEQ linear phase EQ plugin

Full-featured linear phase EQ with interactive graphical curve display.
FIR-based processing (8192-tap), 8 parametric bands, multi-platform
CI/CD (Windows/macOS/Linux), InstaDrums visual style.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

README.md

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+# InstaLPEQ
+
+Free, open-source linear phase EQ plugin built with JUCE. Available as VST3, AU, LV2 and Standalone.
+
+![VST3](https://img.shields.io/badge/format-VST3-blue) ![AU](https://img.shields.io/badge/format-AU-blue) ![LV2](https://img.shields.io/badge/format-LV2-blue) ![C++](https://img.shields.io/badge/language-C%2B%2B17-orange) ![JUCE](https://img.shields.io/badge/framework-JUCE-green) ![License](https://img.shields.io/badge/license-GPL--3.0-lightgrey) ![Build](https://github.com/hariel1985/InstaLPEQ/actions/workflows/build.yml/badge.svg)
+
+## Download
+
+**[Latest Release: v1.0](https://github.com/hariel1985/InstaLPEQ/releases/tag/v1.0)**
+
+### Windows
+| File | Description |
+|------|-------------|
+| [InstaLPEQ-VST3-Win64.zip](https://github.com/hariel1985/InstaLPEQ/releases/download/v1.0/InstaLPEQ-VST3-Win64.zip) | VST3 plugin — copy to `C:\Program Files\Common Files\VST3\` |
+| [InstaLPEQ-Standalone-Win64.zip](https://github.com/hariel1985/InstaLPEQ/releases/download/v1.0/InstaLPEQ-Standalone-Win64.zip) | Standalone application |
+
+### macOS (Universal Binary: Apple Silicon + Intel)
+| File | Description |
+|------|-------------|
+| [InstaLPEQ-VST3-macOS.zip](https://github.com/hariel1985/InstaLPEQ/releases/download/v1.0/InstaLPEQ-VST3-macOS.zip) | VST3 plugin — copy to `~/Library/Audio/Plug-Ins/VST3/` |
+| [InstaLPEQ-AU-macOS.zip](https://github.com/hariel1985/InstaLPEQ/releases/download/v1.0/InstaLPEQ-AU-macOS.zip) | Audio Unit — copy to `~/Library/Audio/Plug-Ins/Components/` |
+| [InstaLPEQ-Standalone-macOS.zip](https://github.com/hariel1985/InstaLPEQ/releases/download/v1.0/InstaLPEQ-Standalone-macOS.zip) | Standalone application |
+
+### Linux (x64, built on Ubuntu 22.04)
+| File | Description |
+|------|-------------|
+| [InstaLPEQ-VST3-Linux-x64.zip](https://github.com/hariel1985/InstaLPEQ/releases/download/v1.0/InstaLPEQ-VST3-Linux-x64.zip) | VST3 plugin — copy to `~/.vst3/` |
+| [InstaLPEQ-LV2-Linux-x64.zip](https://github.com/hariel1985/InstaLPEQ/releases/download/v1.0/InstaLPEQ-LV2-Linux-x64.zip) | LV2 plugin — copy to `~/.lv2/` |
+| [InstaLPEQ-Standalone-Linux-x64.zip](https://github.com/hariel1985/InstaLPEQ/releases/download/v1.0/InstaLPEQ-Standalone-Linux-x64.zip) | Standalone application |
+
+> **macOS note:** Builds are Universal Binary (Apple Silicon + Intel). Not code-signed — after copying the plugin, remove the quarantine flag in Terminal:
+> ```bash
+> xattr -cr ~/Library/Audio/Plug-Ins/VST3/InstaLPEQ.vst3
+> xattr -cr ~/Library/Audio/Plug-Ins/Components/InstaLPEQ.component
+> ```
+
+## Features
+
+### Linear Phase EQ
+- True linear phase processing using symmetric FIR convolution
+- Zero phase distortion at any gain setting
+- 8192-tap FIR filter (configurable: 4096 / 8192 / 16384)
+- DAW-compensated latency (~93ms at 44.1kHz default)
+- Background thread FIR generation — glitch-free parameter changes
+
+### Interactive EQ Curve Display
+- Logarithmic frequency axis (20 Hz — 20 kHz)
+- Linear gain axis (-24 dB to +24 dB)
+- Click to add EQ nodes (up to 8 bands)
+- Drag nodes to adjust frequency and gain
+- Scroll wheel to adjust Q/bandwidth
+- Right-click for band type selection and delete
+- Double-click to reset band to 0 dB
+- Real-time frequency response curve with glow effect
+- Per-band curve overlay
+
+### Band Types
+- Peak (parametric)
+- Low Shelf
+- High Shelf
+
+### Controls
+- Per-band: Frequency, Gain, Q knobs
+- Master gain (+/- 24 dB)
+- Bypass toggle
+- State save/restore (DAW session recall)
+
+### GUI
+- Dark modern UI matching InstaDrums visual style
+- 3D metal knobs with glow effects (orange for EQ, blue for Q)
+- Carbon fiber background texture
+- Rajdhani custom font
+- Fully resizable window with proportional scaling
+- Animated toggle switches
+- Color-coded EQ bands (8 distinct colors)
+
+## Building
+
+### Requirements
+- CMake 3.22+
+- JUCE framework (cloned to `../JUCE` relative to project)
+
+#### Windows
+- Visual Studio 2022 Build Tools (C++ workload)
+
+#### macOS
+- Xcode 14+
+
+#### Linux (Ubuntu 22.04+)
+```bash
+sudo apt-get install build-essential cmake git libasound2-dev \
+  libfreetype6-dev libx11-dev libxrandr-dev libxcursor-dev \
+  libxinerama-dev libwebkit2gtk-4.1-dev libcurl4-openssl-dev
+```
+
+### Build Steps
+
+```bash
+git clone https://github.com/juce-framework/JUCE.git ../JUCE
+cmake -B build -G "Visual Studio 17 2022" -A x64    # Windows
+cmake -B build -G Xcode                              # macOS
+cmake -B build -DCMAKE_BUILD_TYPE=Release             # Linux
+cmake --build build --config Release
+```
+
+Output:
+- VST3: `build/InstaLPEQ_artefacts/Release/VST3/InstaLPEQ.vst3`
+- AU: `build/InstaLPEQ_artefacts/Release/AU/InstaLPEQ.component` (macOS)
+- LV2: `build/InstaLPEQ_artefacts/Release/LV2/InstaLPEQ.lv2`
+- Standalone: `build/InstaLPEQ_artefacts/Release/Standalone/InstaLPEQ.exe`
+
+## How It Works
+
+InstaLPEQ uses a **FIR-based linear phase** approach:
+
+1. Each EQ band's target magnitude response is computed from IIR filter coefficients (Peak, Low Shelf, or High Shelf)
+2. All band magnitudes are multiplied together to form the combined target response
+3. An inverse FFT converts the magnitude-only spectrum into a symmetric time-domain impulse response
+4. A Blackman-Harris window is applied to minimize truncation artifacts
+5. The FIR filter is applied via JUCE's efficient FFT-based `Convolution` engine
+
+This ensures **zero phase distortion** regardless of EQ settings — ideal for mastering, surgical corrections, and transparent tonal shaping.
+
+## Tech Stack
+
+- **Language:** C++17
+- **Framework:** JUCE 8
+- **Build:** CMake + MSVC / Xcode / GCC
+- **Audio DSP:** juce::dsp (FFT, Convolution, IIR coefficient design)
+- **Font:** Rajdhani (SIL Open Font License)