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/quick-batch.md

@@ -4,9 +4,9 @@ title: Quick Batch Mode
 group: Planning Features
 ---
 
-**Command:** `/gsd-quick-batch [--file <path>] [--jobs auto|N] [--validate] [--research] [--resume <batch-id>]`
+**Command:** `/msd-quick-batch [--file <path>] [--jobs auto|N] [--validate] [--research] [--resume <batch-id>]`
 
-**Purpose:** Batch several `/gsd-quick`-shaped tasks together — one coordinator plans, dispatches, and merges them as a single run, with per-item leaves and deterministic merge ordering (ADR-1239 "Quick-batch binding").
+**Purpose:** Batch several `/msd-quick`-shaped tasks together — one coordinator plans, dispatches, and merges them as a single run, with per-item leaves and deterministic merge ordering (ADR-1239 "Quick-batch binding").
 
 **Requirements:**
 - REQ-QB-01: System MUST accept an inline task list (≥2 items) or `--file <path>`