feat: stage 2, the NPC and its API (API 2)

RunicNPC now spawns its own NPC: Rust's scientist with its ScientistNPC and
ScientistBrain swapped for ours, copying a fixed field list generated from
Rust's unmodified assembly (D232, tools/fieldlist). Profiles live in
data/RunicNPC/profiles.json in the approved shape (D238); placements persist
with each/group respawn (D236) and wait for a missing profile or route
(D237); roamers wander, follow Rust's monument paths, or walk a route (D233,
D234), with our own chase where Rust's needs an AI zone; sentries hold their
spot; NPCs walk home and sleep past 160 m of any player (D235). Spawns wait
for the navmesh and are spread over frames; caps are off by default and the
cost warning is shown instead (D227). The whole PLAN.md section 4 API and its
hooks are in, documented in docs/runicnpc/API.md.

tools/RunicNpcTest.cs is the stage 2 harness; every group passed on both
rigs, and after a plugin reload and a server restart. checkPlugin no longer
counts an override (RunicNpcPlayer.OnDied) as a hook.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

scripts/checkPlugin.js

@@ -179,7 +179,11 @@ function check(source, toml) {
   }
 
   const methods = readMethods(source)
-  const hooks = methods.filter((x) => HOOK_NAME.test(x.name))
+  // An `override` is never a hook: a hook is a plugin method the framework finds by name, and the
+  // plugin class overrides nothing shaped like one. What does override `On*` methods is the NPC's
+  // own classes (RunicNpcPlayer.OnDied overrides Rust's ScientistNPC), and Rust, not the
+  // framework, calls those.
+  const hooks = methods.filter((x) => HOOK_NAME.test(x.name) && !/\boverride\b/.test(x.returns))
   const hookNames = new Set(hooks.map((x) => x.name))
 
   // 1. Every hook the plugin implements is one `rnpc.status` can report on.