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/debug.md

@@ -0,0 +1,53 @@
+---
+name: msd:debug
+description: Systematic debugging with persistent state across context resets
+argument-hint: "[list | status <slug> | continue <slug> | --diagnose] [issue description]"
+allowed-tools:
+  - Read
+  - Write
+  - Bash
+  - Grep
+  - Agent
+  - AskUserQuestion
+---
+
+<objective>
+Debug issues using scientific method with subagent isolation.
+
+**Orchestrator role:** Gather symptoms, spawn msd-debugger agent, handle checkpoints, spawn continuations.
+
+**Flags:**
+- `--diagnose` — Diagnose only. Returns a Root Cause Report without applying a fix.
+
+**Subcommands:** `list` · `status <slug>` · `continue <slug>`
+</objective>
+
+<available_agent_types>
+Valid MSD subagent types (use exact names — do not fall back to 'general-purpose'):
+- msd-debug-session-manager — manages debug checkpoint/continuation loop in isolated context
+- msd-debugger — investigates bugs using scientific method
+</available_agent_types>
+
+<execution_context>
+@~/.claude/msd-core/workflows/debug.md
+</execution_context>
+
+<context>
+User's input: $ARGUMENTS
+
+Parse subcommands and flags from $ARGUMENTS BEFORE the active-session check:
+- If $ARGUMENTS starts with "list": SUBCMD=list, no further args
+- If $ARGUMENTS starts with "status ": SUBCMD=status, SLUG=remainder (trim whitespace)
+- If $ARGUMENTS starts with "continue ": SUBCMD=continue, SLUG=remainder (trim whitespace)
+- If $ARGUMENTS contains `--diagnose`: SUBCMD=debug, diagnose_only=true, strip `--diagnose` from description
+- Otherwise: SUBCMD=debug, diagnose_only=false
+
+Check for active sessions (used for non-list/status/continue flows):
+```bash
+ls .planning/debug/*.md 2>/dev/null | grep -v resolved | head -5
+```
+</context>
+
+<process>
+Execute end-to-end.
+</process>