Add neuron-dev-setup: one-command CORE dev stack onboarding installer

Scaffolds a reproducible, idempotent installer that stands up the four native
launchd core services (soul :7770, engram :8742, mcp-wrapper :17779,
mcp-proxy :7779), seeds a fresh engram with the genesis identity via forge, and
installs the Claude Code config (neuron agent + core hooks + local MCP). Fully
templated to the invoking user's $HOME; Anthropic key prompted and stored in
Keychain; no secrets committed. Personal automations and synapse-dependent hooks
excluded from core.

neuron-dev-setup/templates/launchagents/ai.neuron.mcp-wrapper.plist.tmpl

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>Label</key>
+    <string>ai.neuron.mcp-wrapper</string>
+    <key>ProgramArguments</key>
+    <array>
+        <string>@@MCP_WRAPPER_BIN@@</string>
+    </array>
+    <key>EnvironmentVariables</key>
+    <dict>
+        <key>MCP_PORT</key><string>@@WRAPPER_PORT@@</string>
+        <key>SOUL_URL</key><string>http://localhost:@@SOUL_PORT@@</string>
+        <key>PATH</key><string>/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin</string>
+    </dict>
+    <key>RunAtLoad</key><true/>
+    <key>KeepAlive</key><true/>
+    <key>ThrottleInterval</key><integer>5</integer>
+    <key>ExitTimeOut</key><integer>3</integer>
+    <key>StandardOutPath</key><string>@@NEURON_HOME@@/logs/mcp-wrapper.out.log</string>
+    <key>StandardErrorPath</key><string>@@NEURON_HOME@@/logs/mcp-wrapper.err.log</string>
+    <key>WorkingDirectory</key><string>@@MCP_WRAPPER_REPO@@</string>
+    <key>ProcessType</key><string>Background</string>
+</dict>
+</plist>