feat: wire Ida Faber roster smoke

[JOY (JOY)]

Summary

• Wire the 3 imported Ida Faber body variants into the prototype roster by generating project-owned wrapper prefabs/materials under Assets/_SecondSpawn.
• Expand the hub prototype spawner from 10 to 13 permanent NPC markers so the new bodies appear in Play Mode.
• Fix the Nakama runtime registration path by registering top-level RPC functions directly, while preserving explicit secret checks on protected mutation/setup RPCs.
• Document the Unity best-practice audit triage, UI Toolkit/uGUI decision boundary, platform targeting notes, and the client-safe society tick prototype boundary.

Verification

• npm.cmd run build in backend/nakama: pass
• npm.cmd test in backend/nakama: pass after build/test were run sequentially
• npx.cmd markdownlint-cli2 ...: pass for changed docs
• git diff --check origin/dev...HEAD: pass
• em-dash scan on changed docs: pass
• Unity MCP Play Mode smoke: active scene ZoneTest_Hub, _PermanentNpcMarkers spawned with 13 children, Nakama container healthy, Unity console 0 errors after stop/clear; observed one known Visual Studio UDP warning and transient Unity beta GC-handle asserts during Play Mode stop with no stacktrace

Local review fallback

• Checked Nakama boundary changes against project hard rules: Unity still calls Nakama only, no provider keys in client, secondspawn_npc_seed, actor memory consolidation, and relationship update remain protected by explicit server-side secret checks.
• secondspawn_npc_society_tick is intentionally client-callable for the current Play Mode prototype and returns scheduling candidates only; authoritative mutation still goes through validated intent/storage paths.

Notes

• PR feat: manage NPC society decision queues #208 was merged into dev; PR docs: organize public GitBook navigation #222 was already merged. Draft PRs test: cover NPC state of mind surfaces #205 and fix: polish prototype combat and chat presentation #191 were left untouched because they are still draft / pending Unity validation.