feat(tools): add Command Code command adapter for /opsx-* commands (#1622)

* feat(tools): add Command Code command adapter for /opsx-* commands

Command Code documents custom slash commands under
`.commandcode/commands/`, where the command name is the markdown
filename without its `.md` extension (see
https://commandcode.ai/docs/reference/slash-commands). That is the same
flat naming Cursor and OpenCode use, so a standard flat adapter writing
`.commandcode/commands/opsx-<id>.md` registers `/opsx-<id>`.

Registering the adapter flips Command Code from `none` to
`adapter-backed`, so with the default `both` delivery `openspec init`
now generates OpenSpec commands alongside the skills it already installs
under `.commandcode/skills/`.

Builds on #1613, which registered Command Code as a skills-only tool.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* fix(tools): preserve Command Code command arguments

* test(command-code): cover commands-only delivery and openspec update

Addresses review: prove the Command Code adapter survives both the
commands-only init path and the update path, not just default delivery.

- init: delivery=commands generates .commandcode/commands/opsx-explore.md
  and installs no skills.
- update: a detected .commandcode install regenerates the flat
  opsx-<id>.md command (plain Markdown, $ARGUMENTS injected).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

docs/supported-tools.md

@@ -33,7 +33,7 @@ way it loads the file OpenSpec wrote. Find your tool's command path in the
 | `.../opsx-<id>.*` — the filename is the command | `/opsx-<id>` | Every other tool with generated command files, except Amazon Q and Devin |
 | `.devin/workflows/opsx-<id>.md` — read by only one of Devin's two agents | `/opsx-<id>` on Devin Desktop, `/openspec-<skill>` on Devin Local | Devin Desktop\*\*\*\* |
 | `.amazonq/prompts/opsx-<id>.md` — a prompt, not a command | `@opsx-<id>` | Amazon Q Developer |
-| none — skills only | `/openspec-<skill>` | Command Code, CodeArts, ForgeCode, Hermes, MiniMax Code, Mistral Vibe, shared `.agents` |
+| none — skills only | `/openspec-<skill>` | CodeArts, ForgeCode, Hermes, MiniMax Code, Mistral Vibe, shared `.agents` |
 | none — Kimi Code | `/skill:openspec-<skill>` | Kimi Code |
 | none — Codex CLI | `$openspec-<skill>` | Codex ([`/openspec-<skill>` is not recognized](https://github.com/openai/codex/issues/11817)) |
 
@@ -70,7 +70,7 @@ to read the hint.
 | IBM Bob Shell (`bob`) | `.bob/skills/openspec-*/SKILL.md` | `.bob/commands/opsx-<id>.md` |
 | Claude Code (`claude`) | `.claude/skills/openspec-*/SKILL.md` | `.claude/commands/opsx/<id>.md` |
 | Cline (`cline`) | `.cline/skills/openspec-*/SKILL.md` | `.clinerules/workflows/opsx-<id>.md` |
-| Command Code (`command-code`) | `.commandcode/skills/openspec-*/SKILL.md` | Not generated (no command adapter; use skill-based `/openspec-*` invocations) |
+| Command Code (`command-code`) | `.commandcode/skills/openspec-*/SKILL.md` | `.commandcode/commands/opsx-<id>.md` |
 | CodeArts (`codeartsagent`) | `.codeartsdoer/skills/openspec-*/SKILL.md` | Not generated (no command adapter; use skill-based `/openspec-*` invocations) |
 | CodeBuddy (`codebuddy`) | `.codebuddy/skills/openspec-*/SKILL.md` | `.codebuddy/commands/opsx/<id>.md` |
 | Codex (`codex`) | `.agents/skills/openspec-*/SKILL.md` | Not generated (skills-only; use `$openspec-*`) |