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.

tests/vscode-browser-no-node-api.test.cjs

@@ -117,7 +117,7 @@ test('REACHABILITY: browser.js activate() runs against a mock vscode host withou
     const browser = require(BROWSER_PATH);
     const context = { subscriptions: [] };
     assert.doesNotThrow(() => browser.activate(context));
-    assert.ok(registeredCommands['gsd.invoke'], 'gsd.invoke command registered on web too');
+    assert.ok(registeredCommands['msd.invoke'], 'msd.invoke command registered on web too');
     assert.ok(chatCreated, 'chat participant registered on web');
     assert.ok(toolNames.length > 0, 'LM tools registered on web');
     assert.ok(context.subscriptions.length > 0);