docs: add Windows/WSL support research summary

Summarizes GitHub issues, PRs, and community solutions for:
- Windows build availability
- Claude installation detection on Windows
- WSL integration for Claude Code execution
- Custom command/environment variable support

Key references:
- PR winfunc#367 (merged): Windows binary detection
- Issue winfunc#78: Community fix v4.2 with WSL bridge
- Issue winfunc#186: Shell environment detection proposal
- Issue winfunc#400: Custom command support request

Author: jms830

WINDOWS_WSL_RESEARCH.md

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+# Windows & WSL Support Research for Opcode (Claudia)
+
+## Summary
+
+This document summarizes the research findings from winfunc/opcode GitHub issues, PRs, and community forks regarding:
+1. Windows build availability
+2. Claude installation detection on Windows
+3. WSL integration for Claude Code execution
+
+---
+
+## 1. Windows Build Availability
+
+### Current State
+- **No official Windows builds in releases** - Major pain point for users
+- Multiple issues requesting Windows builds: #301, #332, #370, #219, #369
+
+### Community Solutions
+
+#### Issue #370 - Chinese user provided Windows 0.20 build
+- Fixed compilation and installation failure
+- Fixed local Claude code recognition
+- Provided both `.exe` and setup installer
+- Status: Open (community contribution, not merged)
+
+#### Issue #78 - Comprehensive Community Fix v4.2 by @Kirchlive
+**Gist:** https://gist.github.com/Kirchlive/184cdd96a56bfd7a6c67997836495f3c
+
+Files included:
+- `2-claude_binary_patch.rs` - Patched main.rs accepting any Claude version
+- `3-setup-windows.bat` - Creates WSL bridge script
+- `4-start-claudia.bat` - Launcher with pre-flight checks
+- `5-apply-patches.bat` - Build script patches
+
+Key features:
+- WSL bridge via `claude.bat` in `%APPDATA%\npm`
+- Automatic Claude CLI version detection from WSL
+- Filters unsupported parameters (`--system-prompt`, `--no-color`)
+- Supports multiple WSL distributions
+
+#### Issue #352 - AppImage on WSL2 Workaround by @mf
+Run the Linux AppImage release directly in WSL2:
+```bash
+apt install libgles2
+# Extract and run AppImage
+./AppImage --appimage-extract
+```
+
+---
+
+## 2. Claude Installation Detection on Windows
+
+### Merged Fix: PR #367 by @Asm3r96
+**Status: MERGED into main**
+
+Added Windows support via conditional compilation:
+- `#[cfg(windows)]` for `try_which_command()` using `where` instead of `which`
+- `#[cfg(windows)]` for `find_nvm_installations()` checking `NVM_HOME`
+- `#[cfg(windows)]` for `find_standard_installations()` with Windows paths
+
+Windows paths checked:
+- `%USERPROFILE%\.claude\local\claude.exe`
+- `%USERPROFILE%\.local\bin\claude.exe`
+- `%APPDATA%\Roaming\npm\claude.cmd`
+- `%USERPROFILE%\.yarn\bin\claude.cmd`
+- `%USERPROFILE%\.bun\bin\claude.exe`
+
+### Related Open PRs/Issues
+
+#### PR #360 - Windows compatibility (by @hexbee)
+Additional improvements:
+- Replace Unix `which` with Windows `where`
+- Support Windows environment variables (`USERPROFILE` vs `HOME`)
+- Handle `.cmd`, `.exe` extensions
+- Detect Program Files directories
+
+#### PR #348 - Improve Claude installation detection (by @ollieb89)
+Focus on better detection logic for Windows
+
+#### Issue #369 - Build Error on Windows 11
+Missing `installation_type` field in `ClaudeInstallation` struct
+**Fixed by PR #374** (merged)
+
+---
+
+## 3. WSL Integration
+
+### The Core Problem (Issue #168)
+> "Claude code can only be installed on Windows via WSL... how can I run Claude code successfully in the Claudia desktop?"
+
+### Community WSL Bridge Solution (from Issue #78)
+
+The `claude.bat` bridge script:
+```batch
+@echo off
+setlocal enabledelayedexpansion
+
+REM Configuration - set your WSL distro
+SET "WSL_DISTRO="
+
+REM Version check - get real version from WSL claude
+if /I "%~1" == "--version" (
+    for /f "delims=" %%i in ('wsl bash -lc "~/.npm-global/bin/claude --version"') do set "CLAUDE_VERSION=%%i"
+    echo !CLAUDE_VERSION!
+    exit /b 0
+)
+
+REM Filter unsupported arguments
+REM Skip: --system-prompt, --no-color
+
+REM Execute via WSL
+if defined WSL_DISTRO (
+    wsl -d "%WSL_DISTRO%" bash -lc "~/.npm-global/bin/claude !CMD!"
+) else (
+    wsl bash -lc "~/.npm-global/bin/claude !CMD!"
+)
+```
+
+### Issue #137 - Official WSL Support Request
+> "Currently there is a community fix... but we just can't get it to work because of the number of steps involved. Is there a plan for official WSL support?"
+
+**Status: Open, no official response**
+
+### Issue #186 - Windows Shell Support PR by @alexiokay
+**Key improvements proposed:**
+- New `shell_environment.rs` module for Windows shell detection
+- Automatic detection of Git Bash, WSL, PowerShell
+- Proper environment setup for Claude Code on Windows
+- Better error messages with instructions
+
+---
+
+## 4. Feature Request: Custom Command & Environment Variables
+
+### Issue #400 - Support for Custom Claude Execution Command
+Use case: Integration with [claude-code-router](https://github.com/musistudio/claude-code-router)
+
+**Proposed solutions:**
+
+#### Option 1: Custom Claude Binary Path (Recommended)
+```
+Settings → General → Claude Code Command
+[ccr code] (default: claude)
+```
+
+#### Option 2: Custom Environment Variables
+```
+Settings → Advanced → Custom Environment Variables
+ANTHROPIC_BASE_URL=https://my-proxy.com/
+CLAUDE_CODE_MAX_OUTPUT_TOKENS=20000
+```
+
+#### Option 3: Whitelist Configuration
+Allow users to extend the environment variable whitelist via config file.
+
+---
+
+## 5. Active Forks with Recent Changes
+
+| Fork | Last Updated | Notable Changes |
+|------|--------------|-----------------|
+| namastexlabs/opcode | Dec 4, 2025 | Tauri event listener fixes |
+| Rixmerz/nova | Dec 5, 2025 | Rebranded, purple theme, haiku model, unified ClaudeOptions API |
+| tbarstow-tw/opcode-pm | Dec 4, 2025 | BMAD framework documentation |
+| DigitalNomad-Chat/opcode | Dec 4, 2025 | Active development |
+| zhu976/opcode-i18n | Dec 2, 2025 | Chinese i18n support |
+
+---
+
+## 6. Recommended Implementation Path
+
+### For Windows Builds
+1. Add GitHub Actions workflow for Windows builds (requested in #194, #226)
+2. Include the merged Windows detection code from PR #367
+3. Fix icon format issues (#75, #276, #262)
+
+### For WSL Integration
+1. Implement shell environment detection (from PR #186)
+2. Add settings UI for:
+   - Shell preference (PowerShell / Git Bash / WSL)
+   - WSL distribution selection
+   - Custom Claude command path
+3. Create WSL bridge in Rust (not batch file) for better integration
+
+### For Multiple Claude Installations
+1. Already implemented: `list_claude_installations()` API endpoint
+2. Add UI dropdown in settings to select preferred installation
+3. Store preference in `app_settings` table
+
+---
+
+## 7. Key Files to Reference
+
+### In winfunc/opcode main branch:
+- `src-tauri/src/claude_binary.rs` - Windows detection already merged
+- `src-tauri/src/commands/claude.rs` - Command execution (needs WSL support)
+
+### Community Gist (v4.2):
+- https://gist.github.com/Kirchlive/184cdd96a56bfd7a6c67997836495f3c
+
+### Related PRs to watch:
+- #186 - Shell environment detection
+- #360 - Additional Windows compatibility
+- #400 - Custom command/env vars
+- #407 - Tauri event listener fixes (namastexlabs)