refactor: hard-fork GSD -> MSD (Make Software Done)

Mechanical rename produced by scripts/msd-rename.cjs: gsd/Gsd/GSD -> msd/Msd/MSD
across contents and paths, upstream package/repo coordinates -> @golem15/msd-core
and golem15com/msd-core. Deep links into upstream history, sibling upstream
packages, the GSD-2 import feature, CHANGELOG.md and .changeset/ are kept as-is.

Hand edits on top: MSD block-letter banner and logos, LICENSE copyright line,
package/plugin identity, regenerated lockfile, install-tree fixtures, derived
registries and benchmark baseline; migration checksum baseline re-locked
(MSD keeps its own install state, so no install had applied the old sums);
sort-order and regex-escaped expectations in tests adjusted.

hooks/msd-cursor-post-tool.js

@@ -0,0 +1,77 @@
+#!/usr/bin/env node
+// msd-hook-version: {{MSD_VERSION}}
+// msd-cursor-post-tool.js — Cursor postToolUse hook (issue #777)
+//
+// Cursor invokes this script after each tool call completes.
+// Protocol: JSON from Cursor on stdin; JSON response on stdout.
+//
+// Input schema (cursor postToolUse):
+//   { tool_name, tool_input, tool_output, duration,
+//     conversation_id, generation_id, model, hook_event_name,
+//     cursor_version, workspace_roots, user_email, transcript_path }
+//
+// Output schema (cursor postToolUse):
+//   { additional_context?: string }   ← injected as context after the tool use
+//
+// Behaviour:
+//   - After a write-class tool that targets .planning/, reminds the agent
+//     to keep STATE.md current.
+//   - Fails open: any error silently exits 0.
+//
+// Cursor docs: https://cursor.com/docs/hooks
+
+'use strict';
+
+const { allow } = require('./lib/hook-exit.js');
+
+const WRITE_TOOL_RE = /write|edit|replace|create|delete|remove|append|apply|patch|insert|mkdir/i;
+const PATH_KEY_RE = /^(path|file|file_?path|filepath|target_?path|target|dir|directory|uri|filename)$/i;
+const PLANNING_PATH_RE = /(^|[\\/])\.planning([\\/]|$)/;
+
+let raw = '';
+const stdinTimeout = setTimeout(() => {
+  // Timeout guard: exit silently rather than hanging.
+  allow(undefined);
+}, 10000);
+
+process.stdin.setEncoding('utf8');
+process.stdin.on('data', (chunk) => { raw += chunk; });
+process.stdin.on('end', () => {
+  clearTimeout(stdinTimeout);
+  try {
+    let input;
+    try { input = JSON.parse(raw || '{}'); } catch { process.stdout.write(JSON.stringify({})); return; }
+
+    const toolName = String(
+      input.tool_name || input.toolName || ''
+    ).toLowerCase();
+
+    const isWrite = WRITE_TOOL_RE.test(toolName);
+    if (!isWrite) { process.stdout.write(JSON.stringify({})); return; }
+
+    // Collect only PATH-bearing field values (not free-form content).
+    const paths = [];
+    const walk = (v, depth) => {
+      if (depth > 5 || paths.length > 64) return;
+      if (Array.isArray(v)) { for (const x of v) walk(x, depth + 1); return; }
+      if (v && typeof v === 'object') {
+        for (const k of Object.keys(v)) {
+          const val = v[k];
+          if (typeof val === 'string' && PATH_KEY_RE.test(k)) paths.push(val);
+          else walk(val, depth + 1);
+        }
+      }
+    };
+    walk(input.tool_input || input.toolInput || {}, 0);
+
+    if (paths.some((p) => PLANNING_PATH_RE.test(p))) {
+      process.stdout.write(JSON.stringify({
+        additional_context:
+          'MSD: .planning/ artifact updated — ensure STATE.md reflects the latest phase and progress.',
+      }));
+      return;
+    }
+  } catch { /* fall through to empty response */ }
+
+  process.stdout.write(JSON.stringify({}));
+});