fix(#2697): replace retired /gsd: prefix with /gsd- in all user-facing text (#2699)

All workflow, command, reference, template, and tool-output files that
surfaced /gsd:<cmd> as a user-typed slash command have been updated to
use /gsd-<cmd>, matching the Claude Code skill directory name.

Closes #2697

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -28,6 +28,8 @@ If you use GSD **as a workflow**—milestones, phases, `.planning/` artifacts, b
 
 ### Fixed
 
+- **End-of-phase routing suggestions now use `/gsd-<cmd>` (not the retired `/gsd:<cmd>`)** — All user-visible command suggestions in workflows (`execute-phase.md`, `transition.md`), tool output (`profile-output.cjs`, `init.cjs`), references, and templates have been updated from `/gsd:<cmd>` to `/gsd-<cmd>`, matching the Claude Code skill directory name and the user-typed slash-command format. Internal `Skill(skill="gsd:<cmd>")` calls (no leading slash) are preserved unchanged — those resolve by frontmatter `name:` not directory name. The namespace test (`bug-2543-gsd-slash-namespace.test.cjs`) has been updated to enforce the current invariant. Closes #2697.
+
 - **`gsd-sdk query` now resolves parent `.planning/` root in multi-repo (`sub_repos`) workspaces** — when invoked from inside a `sub_repos`-listed child repo (e.g. `workspace/app/`), the SDK now walks up to the parent workspace that owns `.planning/`, matching the legacy `gsd-tools.cjs` `findProjectRoot` behavior. Previously `gsd-sdk query init.new-milestone` reported `project_exists: false` from the sub-repo, while `gsd-tools.cjs` resolved the parent root correctly. Resolution happens once in `cli.ts` before dispatch; if `projectDir` already owns `.planning/` (including explicit `--project-dir`), the walk is a no-op. Ported as `findProjectRoot` in `sdk/src/query/helpers.ts` with the same detection order (own `.planning/` wins, then parent `sub_repos` match, then legacy `multiRepo: true`, then `.git` heuristic), capped at 10 parent levels and never crossing `$HOME`. Closes #2623.
 - **Shell hooks falsely flagged as stale on every session** — `gsd-phase-boundary.sh`, `gsd-session-state.sh`, and `gsd-validate-commit.sh` now ship with a `# gsd-hook-version: {{GSD_VERSION}}` header; the installer substitutes `{{GSD_VERSION}}` in `.sh` hooks the same way it does for `.js` hooks; and the stale-hook detector in `gsd-check-update.js` now matches bash `#` comment syntax in addition to JS `//` syntax. All three changes are required together — neither the regex fix alone nor the install fix alone is sufficient to resolve the false positive (#2136, #2206, #2209, #2210, #2212)