v1.32.0

aichat trim --keep-last N: keep the tail of a session intact

Deterministic trim now takes --keep-last N / -k N, which preserves the
last N user turns verbatim while earlier history is trimmed as before.
A turn is a user prompt plus everything that follows it — assistant text,
thinking blocks, tool calls and tool results — up to the next prompt, so
you keep whole, coherent exchanges instead of an arbitrary count of records
that can cut a tool call away from its result.

• Works across Claude trim, Codex trim, and Claude trim-in-place.
• aichat trim forwards the option and selects direct mode when it is
  supplied on its own.
• Internal Claude notifications and injected Codex goal/context messages do
  not start a user turn, so they can't eat your budget of kept turns.
• Existing positional arguments (dry-run, minimum savings, parent file) keep
  their positions; no other trim behavior changes.

Help text and the aichat docs state the user-turn semantics.

Trimming (#261)

Thanks to @mgkvibez for the original implementation and regression coverage
in #256 — both commits are carried into #261, re-shaped to user-turn
boundaries. Thanks to @rickythefox for requesting this in #72; rollover
integration remains a separate follow-up there.

Full changelog: voxtype-v0.3.17...v1.32.0