Wire the skills window's locks to the server

The skills window (U, #130) shows each skill's lock and cycles it on click, but no command exists on this branch yet: player_ui/skills.rs::lock_command returns None. The progression work (#125) adds, on feat/progression-crafting: Command::SetSkillLock { skill, lock }, SetStatLock { stat, lock }, Wear { uid }, Repair { uid }. Once both branches are in feat/alpha-test:

• lock_command: Some(Command::SetSkillLock { skill, lock }).
• Stat locks: a lock chip per row in the character window's stats table (character_ui.rs::stats), sending SetStatLock.
• Wear the exact item, not any of its kind: Command::Equip { item_id: def.id } becomes Command::Wear { uid } in online/econ/container.rs (drop_item onto the paperdoll, double_click) and player_ui/context.rs (Wield / Wear entries; adjust its test).
• A "Repair" entry in the context menu for damaged gear (Repair { uid }), and the tooltip's durability from uo_proto::craft::durability(def, &props).
• GameEvent::SkillGained / StatGained into the journal (GameLog::say, green), and the skills window redraws on the next sheet.