Ship another application icon in packaged builds

[BeckettFrey]

Narrowed to the icon only. The splash credit line that originally rode along with this is now #170 (merged).

Correction to the original framing

An earlier version of this description claimed the packaged-build icon was broken. That was wrong — tasks.py has always passed --icon on every platform:

• tasks.py:189 — Windows: --icon ./assets/voxkit.ico
• tasks.py:99 — macOS: --icon ./assets/voxkit.icns
• installer/windows/VoxKit.iss:29 — SetupIconFile=..\..\assets\voxkit.ico

The .exe in Explorer, the Start menu, and the installer already carried an icon. This PR does not fix that, because it was not broken.

What this actually changes

1. The icon now appears while the app is running — including under uv run main.py. Qt needs it set explicitly and nothing ever called setWindowIcon. main.py sets it at the QApplication level, src/voxkit/gui/__init__.py at the window level; Qt needs both.

2. assets/ is bundled into frozen builds via --add-data, so (1) also holds in a packaged build. get_assets_root() handles the _MEIPASS case exactly as the existing get_config_root() does.

3. New icon art — assets/vk.ico and assets/vk.png, added alongside the existing voxkit.ico / voxkit.icns / voxkit.png rather than replacing them.

4. A --icon fallback in scripts/build.py for direct invocation without the flag. The invoke tasks always pass --icon, so this never fires on the shipping path.

Open question: do we want a new icon?

This is the part worth an actual decision, and it is independent of the plumbing above. Because the PR adds a second icon set instead of replacing the first, the two are now wired to different surfaces:

Surface	Icon used	Set by
.exe in Explorer / Start menu / pinned shortcut	voxkit.ico (existing)	tasks.py:189
Installer	voxkit.ico (existing)	VoxKit.iss:29
macOS app bundle	voxkit.icns (existing)	tasks.py:99
Running window + taskbar + dev server	vk.ico / vk.png (new)	get_app_icon_path()

As it stands, a Windows user sees the old icon on the shortcut and the new one once the window opens. That wants resolving either way:

• Keep the new art → repoint tasks.py and VoxKit.iss at vk.*, retire voxkit.*.
• Keep the old art → drop vk.* and point get_app_icon_path() at voxkit.ico / voxkit.png.

Notes for review

• assets/vk.png is 4 MB and is the non-Windows runtime icon. That is a lot of weight in every bundle for an icon; downsizing is worth doing whichever art wins.
• Unverified: no packaged build has been produced. The runtime icon path needs a real PyInstaller run to confirm _MEIPASS resolution actually lands.

Related

• Add university credit line to the first-launch splash dialog #170 — splash credit line, split out of this (merged)
• Gray out Train Aligners until a dataset has manual alignments #166 — Train Aligners gating (open)
• Render the word tier above the phone tier in TextGrid timelines #168, Default W2TG "Use Speaker Adaptation" to on #167 — the other splits from MVP polish: W2TG default, tier order, app branding #163 (merged)
• MVP polish: W2TG default, tier order, app branding #163 — the original combined PR (closed in favor of these splits)