bug: Release binaries are missing frontend assets (0-byte index.html served on web UI)

[wzli]

Summary

A user encountered this issue when running the official v1.1.3 precompiled release binary (explo-linux-arm64) on Termux/Linux. Navigating to the Web UI (http://localhost:7288 or via reverse proxy) returns an HTTP 200 OK response with a 0-byte empty page, rendering the Web UI unusable.

Root Cause / Investigation (AI-assisted investigation)

Inspecting .github/workflows/release.yml shows that the Create Release workflow step creates a dummy file to satisfy go:embed:

- name: Create dummy dist directory
  run: mkdir -p src/web/dist && touch src/web/dist/index.html

Because npm run build is never executed in src/web/frontend prior to go build during the release workflow, the embedded dist/ filesystem contains only a 0-byte empty index.html. While the Docker build correctly compiles the frontend, all standalone GitHub release binaries ship without the React assets.

Suggested Fix

In .github/workflows/release.yml, setup Node.js and build the frontend assets before running go build:

- name: Setup Node.js
  uses: actions/setup-node@v4
  with:
    node-version: '20'

- name: Build frontend assets
  run: |
    cd src/web/frontend
    npm ci
    npm run build

Building the binary after compiling the frontend produces a functional ~24MB binary with the full embedded React Web UI.

[wzli]

Additional Finding: Missing search_ytmusic.py helper script

When configuring YouTube/YouTube Music downloads, Explo attempts to execute python3 search_ytmusic.py via exec.Command (src/downloader/youtube.go#L110):

cmd := exec.Command("python3", "search_ytmusic.py", query, "1")

If search_ytmusic.py is not manually placed in Explo's working directory, Python fails with [Errno 2] No such file or directory (exit status 2), logging:

WARN ytmusicapi subprocess failed: exit status 2

Suggested Fix:
Embed search_ytmusic.py via //go:embed or write it to WEB_DATA_PATH at runtime (similar to how config/covers are handled), or pass the absolute path to the script.