daemon: read CLAWDEX_SCALE env var to override window scale

[MondoBoricua]

What

Adds a CLAWDEX_SCALE env var that lets users override the on-screen pet size without rebuilding from source. Default behavior is unchanged.

Why

The default 0.75 scale (hardcoded in PetWindow.init) looks great on most setups but feels oversized on some screens — I ended up patching the source locally to get a smaller sprite. Figured an env var would save the next person that same dance, since the pattern already exists in the daemon (CLAWDEX_SOCK).

How

main.swift reads CLAWDEX_SCALE once at startup, parses as Double, rejects NaN/infinity, clamps to 0.25–4.0, and passes the result into the existing PetWindow(scale:) initializer. No CLI flag, no socket protocol changes, no new types — same pattern as the existing CLAWDEX_SOCK handling a few lines below.

let scale: CGFloat = {
    guard let raw = ProcessInfo.processInfo.environment["CLAWDEX_SCALE"],
          let value = Double(raw), value.isFinite else { return 0.75 }
    return CGFloat(min(max(value, 0.25), 4.0))
}()
window = PetWindow(scale: scale)

The README gets a small Customization section reusing the scale guide that's already in the PetWindow.swift comment (0.5 pixel-perfect / 0.75 default / 1.0 2× pixel-doubled) plus a launchd plist snippet to persist it across reboots.

Behavior

CLAWDEX_SCALE	Effect
unset	PetWindow(scale: 0.75) — identical to today
0.5	smaller, pixel-perfect on Retina
1.0	larger, 2× pixel-doubled
foo / NaN / empty	falls back to 0.75
0.01 / 999	clamped to 0.25 / 4.0

Tested

• swift build -c release clean
• Ran daemon with CLAWDEX_SCALE=0.5 and CLAWDEX_SCALE=1.0 — sprite resized correctly, state machine + dragging still work
• Ran with unset / garbage values — falls back to 0.75 as expected
• macOS 26 (Tahoe), Swift 6.3.2, Apple Silicon

Out of scope (happy to follow up if you want)

• Live reload: change requires daemon restart (launchctl kickstart -k gui/\$(id -u)/dev.clawdex.daemon)
• CLI flag like clawdex wake --scale 0.5 — would need socket protocol additions, felt too heavy for this
• Per-pet scale in pet.json — different design question (whose preference wins?)

Thanks for clawdex by the way — it's great.

[Copilot]

Pull request overview

Adds an optional CLAWDEX_SCALE environment variable so users can adjust the pet window scale at daemon startup without recompiling, mirroring the existing CLAWDEX_SOCK pattern. The value is parsed as a Double, validated against NaN/infinity, and clamped to 0.25–4.0. README gets a new Customization section documenting the variable plus a launchd plist snippet.

Changes:

• Read and validate CLAWDEX_SCALE in AppDelegate.applicationDidFinishLaunching, passing the result to PetWindow(scale:).
• Document the new env var, scale guidance, and launchd persistence in README.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
Sources/ClawdexApp/main.swift	Parse CLAWDEX_SCALE, fall back to 0.75 on invalid input, clamp to [0.25, 4.0], pass into PetWindow.
README.md	Add Customization section explaining CLAWDEX_SCALE and launchd plist usage.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.