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/security-enforcement.md

@@ -4,7 +4,7 @@ title: Security Enforcement
 group: v1.31 Features
 ---
 
-**Command:** `/gsd-secure-phase <N>`
+**Command:** `/msd-secure-phase <N>`
 
 **Purpose:** Threat-model-anchored security verification for phase implementations.
 
@@ -12,7 +12,7 @@ group: v1.31 Features
 - REQ-SEC-01: System MUST perform threat-model-anchored verification (not blind scanning)
 - REQ-SEC-02: System MUST support configurable OWASP ASVS verification levels (1-3)
 - REQ-SEC-03: System MUST block phase advancement based on configurable severity threshold
-- REQ-SEC-04: System MUST spawn `gsd-security-auditor` agent for analysis
+- REQ-SEC-04: System MUST spawn `msd-security-auditor` agent for analysis
 
 **Produces:**
 | Artifact | Description |
@@ -21,7 +21,7 @@ group: v1.31 Features
 
 **Process:**
 1. **Model** — Build threat model from phase implementation context
-2. **Audit** — Spawn `gsd-security-auditor` to verify against threat model
+2. **Audit** — Spawn `msd-security-auditor` to verify against threat model
 3. **Gate** — Block phase advancement if findings meet or exceed `security_block_on` severity
 
 **Config:**