fix: harden sqlite queue path handling

[giscebot]

Summary

• Expand ~ in the SQLite queue DB path before opening the database.
• Recreate the DB parent directory immediately before each SQLite connection, so long-running workers recover if the state directory is missing at claim time.
• Add focused queue tests for literal ~ paths and missing parent directories.

Fixes #6.
Fixes #8.

Tests

• pytest -q tests/test_queue.py
• pytest -q

Notes

• No TASK-xxxxx was provided in the issue. I could not create an ERP task from this runtime because no ERP connection arguments/token are configured for pygisceclient.