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.

commands/msd/docs-update.md

@@ -0,0 +1,49 @@
+---
+name: msd:docs-update
+description: Generate or update project documentation verified against the codebase
+argument-hint: "[--force] [--verify-only]"
+allowed-tools:
+  - Read
+  - Write
+  - Edit
+  - Bash
+  - Glob
+  - Grep
+  - Agent
+  - AskUserQuestion
+requires: [update]
+---
+<objective>
+Generate and update up to 9 documentation files for the current project. Each doc type is written by a msd-doc-writer subagent that explores the codebase directly — no hallucinated paths, phantom endpoints, or stale signatures.
+
+Flag handling rule:
+- The optional flags documented below are available behaviors, not implied active behaviors
+- A flag is active only when its literal token appears in `$ARGUMENTS`
+- If a documented flag is absent from `$ARGUMENTS`, treat it as inactive
+- `--force`: skip preservation prompts, regenerate all docs regardless of existing content or MSD markers
+- `--verify-only`: check existing docs for accuracy against codebase, no generation (full verification requires Phase 4 verifier)
+- If `--force` and `--verify-only` both appear in `$ARGUMENTS`, `--force` takes precedence
+</objective>
+
+<execution_context>
+@~/.claude/msd-core/workflows/docs-update.md
+</execution_context>
+
+<context>
+Arguments: $ARGUMENTS
+
+**Available optional flags (documentation only — not automatically active):**
+- `--force` — Regenerate all docs. Overwrites hand-written and MSD docs alike. No preservation prompts.
+- `--verify-only` — Check existing docs for accuracy against the codebase. No files are written. Reports VERIFY marker count. Full codebase fact-checking requires the msd-doc-verifier agent (Phase 4).
+
+**Active flags must be derived from `$ARGUMENTS`:**
+- `--force` is active only if the literal `--force` token is present in `$ARGUMENTS`
+- `--verify-only` is active only if the literal `--verify-only` token is present in `$ARGUMENTS`
+- If neither token appears, run the standard full-phase generation flow
+- Do not infer that a flag is active just because it is documented in this prompt
+</context>
+
+<process>
+Execute end-to-end.
+Preserve all workflow gates (preservation_check, flag handling, wave execution, monorepo dispatch, commit, reporting).
+</process>