* fix(daemon): remove --no-session from pi adapter to persist session files
The pi agent was the only adapter explicitly passing `--no-session`
in its `buildArgs`, preventing pi from writing session files.
All other adapters either run in single-shot mode by design or use
the ACP JSON-RPC session lifecycle without suppressing persistence.
Removing `--no-session` lets `--mode rpc` retain its default behavior
of writing session state, which is needed for multi-prompt continuity
and matches the rest of the harness ecosystem.
* test(daemon): add pi buildArgs regression tests; fix docs for --no-session removal
- Adds test for pi.buildArgs base shape: returns ["--mode", "rpc"]
and does not include --no-session (prevents regression).
- Adds test for --model and --thinking option passthrough.
- Updates pi-rpc.ts lifecycle comment to remove [--no-session].
- Updates README.md and all localized READMEs to reflect the
corrected pi CLI invocation.
