chore(skills): add create-workspace skill for topic jj workspaces

.claude/skills/create-workspace/SKILL.md

@@ -0,0 +1,64 @@
+---
+name: create-workspace
+description: Create a new shared topic workspace with fresh jj workspaces for agent-os and secure-exec under ~/workspaces/{topic}/, each on a new change off latest main. Trigger ANY time the user says "create a new workspace" (or asks for a new worktree/workspace for a topic).
+---
+
+# Create a topic workspace (agent-os + secure-exec)
+
+Creates `~/workspaces/<topic>/` with sibling jj workspaces `agentos/` and
+`secure-exec/`, each with a fresh working copy on top of the freshly fetched
+`main@origin`.
+
+Derive `<topic>` as a short kebab-case slug from the user's ask (e.g.
+"create a new workspace for the poll rework" → `poll-rework`). If the user
+did not imply a topic, ask for one.
+
+## Steps
+
+```bash
+topic=<topic>
+mkdir -p ~/workspaces/$topic
+
+# agent-os
+cd ~/agent-os
+jj git fetch
+jj workspace add --name $topic ~/workspaces/$topic/agentos
+cd ~/workspaces/$topic/agentos
+jj new 'main@origin' -m "wip: $topic"
+
+# secure-exec
+cd ~/secure-exec
+jj git fetch
+jj workspace add --name $topic ~/workspaces/$topic/secure-exec
+cd ~/workspaces/$topic/secure-exec
+jj new 'main@origin' -m "wip: $topic"
+```
+
+If `jj workspace add` fails because the name is taken, suffix it
+(`$topic-2`) — the directory path stays as requested.
+
+## STRICT: these workspaces ARE the session's working directories
+
+From the moment this skill runs, ALL work for the rest of the session happens
+inside `~/workspaces/<topic>/agentos` and `~/workspaces/<topic>/secure-exec`.
+
+- NEVER edit, build, or run jj/git state-changing commands in the main
+  checkouts (`~/agent-os`, `~/secure-exec`) or in any other workspace for the
+  remainder of the session. They belong to other sessions; their working
+  copies are live shared state.
+- The ONLY allowed operations against the main checkouts are read-only git
+  plumbing that does not touch a working copy (e.g. `git -C ~/agent-os
+  fetch`, `gh` calls, creating a temporary `git worktree` for assembling a
+  PR branch).
+- If a command needs a repo path, spell out the workspace path explicitly —
+  do not rely on a remembered cwd.
+
+## Notes
+
+- The two workspaces are siblings, so agent-os local dep mode works
+  unchanged: run `just secure-exec-local` inside the new `agentos/` workspace
+  to point deps at `../secure-exec`.
+- `dist/`, `vendor/`, `node_modules/`, registry artifacts are gitignored and
+  NOT present in a fresh workspace — run `pnpm install` (both repos) and the
+  builds the task needs (see the repo CLAUDE.md "Testing a local build"
+  sections) before relying on them.