tools: add wiki-gen — regenerates topic-contract AUTOGEN blocks

Generates the markdown table inside <!-- BEGIN AUTOGEN: topic-contract -->
blocks in nodes/<n>/wiki/Reference-Contracts.md from the canonical registry
at src/commands/index.js. Replaces the agent-written placeholders the wiki
uplift left behind.

- Accepts both labelled and unlabelled END markers; rewrites to canonical
  '<!-- END AUTOGEN: topic-contract -->' on regeneration so future runs are
  consistent.
- --check mode for CI (exit 1 if any block is out of date).
- Out of scope for now: data-model AUTOGEN block (requires instantiating
  the domain; the 9 agent-written placeholders for that block stay until
  a follow-up tool lands).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tools/wiki-gen/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@evolv/wiki-gen",
+  "version": "0.1.0",
+  "private": true,
+  "description": "Generate the AUTOGEN sections of nodes/<n>/wiki/Reference-Contracts.md from commands/index.js",
+  "bin": {
+    "evolv-wiki-gen": "bin/wiki-gen.js"
+  },
+  "scripts": {
+    "test": "node --test test/*.test.js"
+  },
+  "license": "UNLICENSED"
+}