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.

docs/features/project-initialization.md

@@ -4,7 +4,7 @@ title: Project Initialization
 group: Core Features
 ---
 
-**Command:** `/gsd-new-project [--auto @file.md]`
+**Command:** `/msd-new-project [--auto @file.md]`
 
 **Purpose:** Transform a user's idea into a fully structured project with research, scoped requirements, and a phased roadmap.
 
@@ -43,4 +43,4 @@ group: Core Features
 - Research agents have web search capability for current ecosystem information
 - Granularity setting controls phase count: `coarse` (2-4), `standard` (4-6), `fine` (6-10)
 - `--auto` mode extracts all information from the provided document without interactive questioning
-- Existing codebase context (from `/gsd-map-codebase`) is loaded if present
+- Existing codebase context (from `/msd-map-codebase`) is loaded if present