Packaging rework (#531)

* fix: get rid of title view jank on latest beta

* Count the number of installs for each plugin (#557)

* Bump aiohttp from 3.8.4 to 3.8.5 in /backend (#558)

* fix: include Decky version in request for index.js

This avoids the If-Modified-Since logic in aiohttp and ensures Steam doesn't cache old JS,
even if the timestamps are normalized.

* fix: clean up shellcheck warnings in act runner script

* fix: gitignore settings/

* fix: ensure state directories exist when running without the installer

* feat: determine root directory correctly when running from in-tree

* fix: fix typo in CI script

* refactor: build a proper Python package with poetry

* refactor: move decky_plugin under the poetry structure

There's no need to special case it anymore, just treat it like any other Python module.

* sandboxed_plugin: better fix, attempt 2

---------

Co-authored-by: AAGaming <aagaming@riseup.net>
Co-authored-by: Party Wumpus <48649272+PartyWumpus@users.noreply.github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

backend/pyinstaller.spec

@@ -0,0 +1,30 @@
+import os
+from PyInstaller.building.build_main import Analysis
+from PyInstaller.building.api import EXE, PYZ
+from PyInstaller.utils.hooks import copy_metadata
+
+a = Analysis(
+    ['main.py'],
+    datas=[
+        ('locales', 'locales'),
+        ('static', 'static'),
+    ] + copy_metadata('decky_loader'),
+    hiddenimports=['logging.handlers', 'sqlite3', 'decky_plugin'],
+)
+pyz = PYZ(a.pure, a.zipped_data)
+
+noconsole = bool(os.getenv('DECKY_NOCONSOLE'))
+name = "PluginLoader"
+if noconsole:
+    name += "_noconsole"
+
+exe = EXE(
+    pyz,
+    a.scripts,
+    a.binaries,
+    a.zipfiles,
+    a.datas,
+    name=name,
+    upx=True,
+    console=not noconsole,
+)