Fix Cydonia mission startup in separate and shared co-op campaigns

[xcomcoopdev]

Summary

Fixes the Cydonia final mission failing to load for the second player in co-op campaigns.

Previously, Cydonia was started through ConfirmCydoniaState, which bypassed the normal ConfirmLandingState co-op mission startup and battle streaming flow. As a result, the initiating player generated the Mars map locally, while the other player never received or loaded it.

Changes

• Added a dedicated co-op startup path for ConfirmCydoniaState.
• Added support for both SEPARATE and SHARED campaigns.
• SEPARATE campaigns now perform the existing two-world craft and squad merge before generating Cydonia.
• SHARED campaigns now generate Cydonia once on the authoritative host and stream the same battle to the client.
• Applied the SHARED soldier control split based on ownerPlayerId.
• Added protection against generating the shared Cydonia map more than once.
• Preserved the original single-player Cydonia startup behavior.
• Added harness commands for opening and confirming the real Cydonia confirmation state.

Regression test

Added:

tools/coop_test/test_cydonia_coop_start.py

The regression test covers:

• Cydonia startup in a SEPARATE co-op campaign.
• Cydonia startup in a SHARED co-op campaign.
• Both players receiving a live battle.
• Both players loading the same mission type.
• Matching map dimensions on both machines.
• Matching map fingerprints on both machines.
• Both players reaching BriefingState.

Testing

The new regression test was run successfully in both campaign modes.

Result:

• SEPARATE campaign: passed
• SHARED campaign: passed