Type integration deploy service

[ethayu]

Summary

• add typed structures for fleet network policies and fleet catalog cache payloads
• narrow YAML/JSON values before runtime fleet and source response construction
• keep GitHub cache/error fallback handling type-safe
• initialize download extraction state explicitly for cleanup

Fixes #228
Part of #201

Verification

• source /opt/ros/humble/setup.bash && source /home/ubuntu/monorepo/controls/sae_2025_ws/install/setup.bash && export PYTHONPATH="$PWD/controls/sae_2025_ws/src/integration:$PWD/controls/sae_2025_ws/src/uav:$PYTHONPATH" && npx --yes pyright controls/sae_2025_ws/src/integration/backend/services/deploy.py --outputjson
• python3 -m compileall controls/sae_2025_ws/src/integration/backend/services/deploy.py
• ruff check --config controls/sae_2025_ws/.ruff.toml controls/sae_2025_ws/src/integration/backend/services/deploy.py
• ruff format --check --config controls/sae_2025_ws/.ruff.toml controls/sae_2025_ws/src/integration/backend/services/deploy.py
• python3 -m pytest -q controls/sae_2025_ws/src/integration/test/test_deploy.py

[ethayu]

Folded into #221 as a separate commit; closing to keep integration backend typing in one PR.