* feat(cli): /reasoning full to show complete thinking, not 10-line clamp
The post-response Reasoning recap box hard-clamped long thinking to the
first 10 lines, so there was no way to see the full reasoning trace after
a turn (live streaming already shows it in full). Add display.reasoning_full
(default off) plus /reasoning full|clamp to toggle it at runtime; the clamp
truncation note now points at the command. Addresses repeated user requests
to show all thinking tokens.
* test(gateway): de-snapshot /reasoning help assertion
The test froze the exact args-hint literal '/reasoning [level|show|hide]',
which the new full/clamp args change to '[level|show|hide|full|clamp]'.
Convert to an invariant: assert /reasoning is in help and carries its core
args, not the exact hint string.
* feat(tui): /reasoning full|clamp parity in tui_gateway
The classic-CLI reasoning_full toggle had no TUI equivalent — typing
/reasoning full in the TUI fell through to parse_reasoning_effort and
errored. The TUI renders thinking as an expand/collapse section (no fixed
10-line recap), so map full -> sections.thinking=expanded (raw, uncapped
via thinkingPreview mode='full') and clamp -> collapsed, persisting
display.reasoning_full for cross-surface config consistency.
