fix(#319,#296): v0.9.8 rebuild — bundle missing deps so backend launches

Issues #319 and #296 reported that the installed v0.9.79 Windows MSI/EXE
crashed on launch with:

    thread 'main' panicked ... failed to setup app: error encountered
    during setup hook: ShadowBroker cannot start: the bundled local
    backend failed to launch.
    technical detail: managed_backend_exited_early:exit code: 103

Root cause: ``backend/pyproject.toml`` declares ``defusedxml>=0.7.1`` and
``PySocks==1.7.1`` as runtime dependencies, but the venv used to build
v0.9.79 (and the initial v0.9.8 publish) had both missing. When
``services/fetchers/aircraft_database.py`` does
``import defusedxml.ElementTree`` at startup, Python raises
``ModuleNotFoundError`` and uvicorn exits, which Tauri reports as
``managed_backend_exited_early``.

Both packages now installed in the build venv. ``main.py`` imports
end-to-end with only the expected ``plane_alert_db.json not found``
warning (runtime-state file, populated on first launch).

Rebuilt artifacts on the maintainer's local machine:

    ShadowBroker_v0.9.8.zip                  6.06 MB
      183bb5cd62b9b9349d95df5ef7696cb6ca810ab4b991fa9dab6f898af4c7a175
    ShadowBroker_0.9.8_x64_en-US.msi       122.4 MB
      fe22f9d51e4360d74c18a7250c2fbb9ed4fa4c7a884b3ac0d04a21115466386b
    ShadowBroker_0.9.8_x64-setup.exe        76.5 MB
      94a0309862e9c81c92cdcbfea8eec9dbb97eef19ded82b26217b397defbc810c

After this merges, the v0.9.8 tag will be force-moved to this commit and
the GitHub release assets replaced so the integrity chain validates
against the working installers instead of the broken ones.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/data/release_digests.json

@@ -38,8 +38,8 @@
     "ShadowBroker_0.9.79_x64_en-US.msi": "e0713c3cdda184cfbea750bfac0d62a35678fec00847e6476f2cac8e7e42046e"
   },
   "v0.9.8": {
-    "ShadowBroker_v0.9.8.zip": "d506f6b8462ccb12096f0cd9462233be58928094240416b65fb3127bdd1f3820",
-    "ShadowBroker_0.9.8_x64-setup.exe": "1115d1f5cf37edd03ea2c21d821c7626e1bf3319c990402aaa0293bca46fea67",
-    "ShadowBroker_0.9.8_x64_en-US.msi": "d4be4cb68c3e6409fff54c225acdcdd08e27d5d6d2b31616d78d2a4f6812991d"
+    "ShadowBroker_v0.9.8.zip": "183bb5cd62b9b9349d95df5ef7696cb6ca810ab4b991fa9dab6f898af4c7a175",
+    "ShadowBroker_0.9.8_x64-setup.exe": "94a0309862e9c81c92cdcbfea8eec9dbb97eef19ded82b26217b397defbc810c",
+    "ShadowBroker_0.9.8_x64_en-US.msi": "fe22f9d51e4360d74c18a7250c2fbb9ed4fa4c7a884b3ac0d04a21115466386b"
   }
 }