Closes#11532.
The docs and CLI help did not say which working directory a resumed
session runs in. That directory controls tools, `@path` references,
project configuration, and context files.
## Changes
- `docs/sessions.md`: states that a session keeps the working directory
it was created in, adds a table mapping each entry point to its working
directory, and describes what happens when that directory no longer
exists. Removes a paragraph that repeated the `--session`/`--fork`
descriptions.
- `docs/cli.md` and `--help`: clearer `--continue`, `--resume`,
`--session`, `--session-id`, and `--fork` descriptions. The help only
mentions the directory where it is not obvious (`--fork`).
- `/resume` and `/import` command descriptions, mirrored in
`docs/slash-commands.md`. `/import` notes that it preserves the session
ID and working directory.
| Entry point | Working directory |
|---|---|
| `--continue` | The current directory |
| `--resume`, `/resume`, `--session`, `/import` | The session's working
directory, which can differ from the current directory |
| `--fork`, or a `--session` ID from another directory that you choose
to fork | The current directory, in a new session |
Behavior was verified against `createSessionManager` in `src/main.ts`,
`SessionManager.open`/`continueRecent`/`forkFrom`, and
`AgentSessionRuntime.importFromJsonl`.
