Add penguin weapon support (OP4, ID 26)

[jkivilin]

Summary

• Add OP4 penguin weapon (ID 26, snark reskin) with weapon select, fire delay, monster entity detection, and enemy search skip
• Weapon config mirrors snark: WEAPON_THROW, range 128-800, SKILL3, ammo on repickup
• No waypoint flag assigned (all 31 usable bits in signed int are taken; penguin is rare)
• Fix GetWeaponSelect to prefer entries matching the active submod when multiple weapons share the same ID (penguin and Arena 9mmsilenced both use ID 26)

ID 26 collision note

Penguin (OP4) and 9mmsilenced (HL:Arena) both use weapon ID 26. This is correct — the engine assigns the same ID slot to different weapons in different mods. They never coexist at runtime since supported_submods filters them (WEAPON_SUBMOD_OP4 vs WEAPON_SUBMOD_ARENA). Penguin is not present in HL:Arena. GetWeaponSelect is updated to be submod-aware so it returns the correct entry for the active mod.

Test plan

• Cross-compile build passes (make test with i686-linux-gnu toolchain)
• Verify penguin pickup/throw works in OP4 multiplayer