refactor(stop): rewrite SKILL.md frontmatter/heading/prose for stop semantics (FW-13, FW-03)

- frontmatter description: 'Terminate...mark it terminated' → 'Stop...hard=terminated, stop options=stopped'
- heading: 'Multi-Agent Delete' → 'Multi-Agent Stop'
- tags: delete → stop
- state machine diagram: delete → stop
- prose: soft/hard delete → soft/hard stop throughout
- stop_session.sh: comments + echo 'delete complete' → 'stop complete'
- create/SKILL.md: companion list 'delete' → 'stop' (2 locations)
- preserved: status=terminated (valid YAML value), terminated_at field, --purge-conversation semantics

skills/tmux-agent-orchestrate-create/SKILL.md

@@ -22,7 +22,7 @@ metadata:
 
 Spawn a new agent (`claude` or `agy`/antigravity-cli) in a **dedicated tmux session** for context-preserving long-running work. The tmux session is the *container*; the agent's session ID is *data* inside the container. **This skill creates the container + starts the agent — but does not resume an old conversation** (use `tmux-agent-orchestrate-resume` for that).
 
-For all agents: the tmux session name is produced by **`lib.sh::derive_session_name`** — the single source of truth shared by create/resume/delete/status/monitor (P0-A). The rule (verbatim from the function):
+For all agents: the tmux session name is produced by **`lib.sh::derive_session_name`** — the single source of truth shared by create/resume/stop/status/monitor (P0-A). The rule (verbatim from the function):
 
 > slug = the **two trailing path components** of the absolute workspace, `_`→`-`, lowercased, joined with `-`; name = `<slug>-creator-<agent>`.
 
@@ -70,7 +70,7 @@ To prevent this, you can run this skill inside an **isolated tmux server** using
 1. **Via Environment Variable**:
    ```bash
    export TMUX_SERVER_NAME=multi-agent-canary
-   # All subsequent commands (create, status, delete, etc.) will run in the isolated 'multi-agent-canary' tmux server.
+   # All subsequent commands (create, status, stop, etc.) will run in the isolated 'multi-agent-canary' tmux server.
    ```
 2. **Via Option Flag**:
    ```bash