docs(create-objectstack): the scaffolded project's own docs name the per-agent install form

`templates/AGENTS.md` and the blank template README both told a project's
future readers to run the bare `npx skills add objectstack-ai/objectstack/skills`,
which prompts for agents interactively — picking "all" there re-creates the
triplicate this card removes, inside the user's own repository.

Both now name the single-agent form, say where the committed copy lives, and
refuse `--all` with the reason.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PbJ5Cy9KDAzeQHo8bsMadG

Author: claude

packages/create-objectstack/src/templates/AGENTS.md

@@ -73,13 +73,19 @@ Run `npm run build` when you need the compiled `dist/objectstack.json` artifact.
 
 ## AI Skills
 
-This project uses ObjectStack skills from `objectstack-ai/objectstack`.
-Install or update skills with the standard [skills CLI](https://skills.sh/):
+This project uses ObjectStack skills from `objectstack-ai/objectstack`. They
+were installed for one agent runtime, live in `.claude/skills/`, and are
+committed with the project. Install or update them with the standard
+[skills CLI](https://skills.sh/), naming your runtime:
 
 ```bash
-npx skills add objectstack-ai/objectstack/skills
+npx skills add objectstack-ai/objectstack/skills --skill '*' --agent claude-code -y
 ```
 
+Adding a second runtime? Re-run it with that runtime's `--agent` name.
+⛔ Do not use `--all`: it writes the same bundle to `.agents/`, `agent/` and
+`.claude/` at once, and all three then land in your next commit.
+
 Skills are triggered automatically based on task context:
 
 | Skill | Trigger Context |

packages/create-objectstack/src/templates/blank/README.md

@@ -140,5 +140,10 @@ covered in [Self-Hosted Deployment](https://objectstack.ai/docs/deployment/self-
 - Add a flow or automation: see `objectstack-automation`.
 - Add an AI agent: see `objectstack-ai`.
 
-Skills are installed with `npx skills add objectstack-ai/objectstack/skills`
-(see `AGENTS.md`) and also show up in the in-IDE assistant catalog.
+Skills live in `.claude/skills/` and are committed with this project, once.
+They are installed one agent runtime at a time (see `AGENTS.md`), and also show
+up in the in-IDE assistant catalog:
+
+```bash
+npx skills add objectstack-ai/objectstack/skills --skill '*' --agent claude-code -y
+```