fix: resolve rcedit path at runtime to fix ENOENT on Windows

[Dyn4sty]

Problem

When electrobun dev or electrobun build runs on Windows and the project has a Windows icon configured, icon embedding into launcher.exe, bun.exe, and the installer EXE silently fails with:

Warning: Failed to embed icon into launcher.exe: Error: Error executing command (D:\a\electrobun\electrobun\package\node_modules\rcedit\bin\rcedit-x64.exe ...):
spawn D:\a\electrobun\electrobun\package\node_modules\rcedit\bin\rcedit-x64.exe ENOENT
The system cannot find the drive specified.

Root cause: The CLI binary is compiled with bun build --compile on the GitHub Actions runner whose workspace is D:\a\electrobun\. Bun's compiler freezes __dirname (inside the bundled rcedit CJS module) to that build-machine path. On any developer machine without a D:\ drive, path.resolve(__dirname, '..', 'bin', 'rcedit-x64.exe') resolves to a non-existent path.

Fix

Replace all three await import("rcedit") call sites with a new spawnRcedit() helper that resolves the rcedit-x64.exe path at runtime using process.execPath:

dirname(process.execPath)/../../rcedit/bin/rcedit-x64.exe

Since electrobun.exe and rcedit are always sibling packages in the consuming project's node_modules/, this path is correct at runtime on any machine, regardless of where the binary was compiled.

Affected call sites

• Icon embedding into launcher.exe (~line 2166)
• Icon embedding into bun.exe (~line 2263)
• Icon embedding into the Windows installer EXE (~line 4310)

Testing

Verified by reproducing the ENOENT locally (no D:\ drive) and confirming all three call sites now correctly resolve to the local node_modules/rcedit/bin/rcedit-x64.exe.