[SOLID] [M13] Migrate game-core/game-ui onto existing role interfaces (stop using concrete World)

[MichaelFisher1997]

Part of #776 — SOLID architecture debt umbrella.
Phase: P2 · Finding: M13

Problem

IWorldSimulation/IWorldRenderView/IWorldTelemetry exist and render_graph.zig uses them correctly. But game-core/game-ui reach past them into the concrete 845-line World, dragging the entire runtime dependency graph.

Evidence

modules/game-core/src/session.zig:228,320,328,355; player.zig:277,386; modules/game-ui/src/screens/world.zig:135,243:

session.zig:228  world.enableSaveManager(...)
session.zig:320  self.world.pauseGeneration()
player.zig:386   world.setBlock(...)
world.zig:135    session.world.setRenderDistance(...)

Fix

Migrate each call site onto the appropriate role interface. One focused PR per caller file is feasible:

• session.zig → IWorldSimulation + IWorldTelemetry
• player.zig → IWorldSimulation
• game-ui/screens/world.zig → IWorldTelemetry

Verification

• nix develop --command zig build test (includes shader validation)
• If rendering-touching: capture headless screenshot baseline before/after (-Dskip-present)
• If behavior-preserving refactor: golden-output test must stay green

Constraints

• Small reviewable PR targeting dev; conventional commit (refactor: / feat:)
• Preserve current behavior unless this issue explicitly changes it
• Keep worker-thread RHI isolation intact (no RHI calls off main thread)

Notes

The role interfaces already exist — this is purely a consumer-side migration. Coordinate with M19 if contracts move to engine-rhi.

Tracking: #776

[github-actions]

I examined the codebase referenced in the M13 issue (session.zig, player.zig, world-runtime/World), confirming the call-site locations, the existence of IWorldSimulation/IWorldRenderView/IWorldTelemetry, and the concrete World (~866 lines) the issue recommends migrating off of, so I could classify it as a well-scoped SOLID refactor and post a concise validation comment.

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