Move GUI deps (napari, PyQt6) to optional dependency group (#208)

* Move napari, PyQt6, napari-animation to optional gui dependency group

Fixes #206. These GUI dependencies cause install failures on headless/HPC
systems. They are now available via `pip install -e ".[gui]"` or `.[all]`.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fix iohub/waveorder dependency conflict and exclude gui from dev

- Pin iohub to git xarray-integration branch to match waveorder's requirement
- Exclude gui extra from dev to avoid PyQt6 build failures in CI

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Alexandr Kalinin <alxndrkalinin@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: alxndrkalinin

pyproject.toml

@@ -20,11 +20,9 @@ classifiers = [
 
 # list package dependencies here
 dependencies = [
-  "iohub[tensorstore]>=0.3.0a5,<0.4",
+  "iohub[tensorstore] @ git+https://github.com/czbiohub-sf/iohub.git@xarray-integration",
   "stitch @ git+https://github.com/ahillsley/stitching@jen",
   "matplotlib",
-  "napari",
-  "PyQt6",
   "natsort",
   "numpy",
   "markdown",
@@ -39,7 +37,6 @@ dependencies = [
   "largestinteriorrectangle",
   "antspyx",
   "pystackreg",
-  "napari-animation",
   "imageio-ffmpeg",
   "dask[array]",
   "toml",
@@ -54,14 +51,16 @@ segment = ["cellpose"]
 
 track = ["ultrack>=0.7.0rc2"]
 
+gui = ["napari", "PyQt6", "napari-animation"]
+
 shard = ["tensorstore"]
 
 build = ["build", "twine"]
 
-all = ["biahub[segment,track,shard,build]"]
+all = ["biahub[segment,track,shard,build,gui]"]
 
 dev = [
-  "biahub[all]",
+  "biahub[segment,track,shard,build]",
   "black==25.1",
   "flake8==7.2",
   "isort==6.0",