Move Invites into Members sub-section row and add layout for extra buttons

[plan3t]

Motivation

• The invites UI was a top-level tab but should live inside the Members page beneath member controls so players can respond to invites near member settings.
• The UI must allow placing additional sub-buttons beside the new Invites button without changing the main tab model.

Description

• Removed the top-level INVITES tab from FactionTab and added a compact label API via getCompactLabel so the main tab row stays concise (src/main/java/com/mcprotector/client/gui/FactionTab.java).
• Added a MemberSection enum and two widgets membersSectionButton and invitesSectionButton, plus helpers layoutMemberSectionButtons and updateMemberSectionButtonState, to create a Members sub-section button row that can host more buttons (src/main/java/com/mcprotector/client/gui/FactionMainScreen.java).
• Moved invite rendering into the Members flow by making renderMembers switch to renderInvites when the sub-section is INVITES, and updated visibility via updateVisibility / updateDynamicVisibility so invite controls only show when Members -> Invites is active.
• Adjusted content layout calculations (getContentStart) to reserve vertical space for the new sub-section row and added scaling helpers panelX / scaledWidth and layout recalculation (recalculateLayout) to keep control sizes responsive.
• Performed related UI refinements: converted many button/field bounds to scaled sizes, tuned tab/button sizing constants, and adjusted the map renderer cell sizing/height heuristics (src/main/java/com/mcprotector/client/gui/FactionMapRenderer.java).

Testing

• Ran ./gradlew compileJava and the project compiled successfully (BUILD SUCCESSFUL).

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Codex Task