v0.32.3

Patch release focused on prompt-cache cost around history compaction boundaries.

Cache stability

Fixed a double cache bust that occurred when the compaction boundary advanced on large sessions: the pass that moved the boundary and the following pass could serve different renderings of the summary marker, paying an avoidable full-prefix re-read (typically 100K+ tokens) on every boundary move. The marker representation is now reconciled deterministically on every pass, so a boundary move costs exactly one bust.
Marker rows are now written with deterministic identifiers, making retries after interrupted writes converge on the same rows instead of duplicating them.
Concurrent processes sharing a session (for example a TUI attached alongside a running server) now serve identical marker renderings instead of briefly diverging.

The synthetic history head is identified structurally rather than by metadata, preventing mispositioned summary markers next to system-delivered notices.
Sessions without a frozen ctx_reduce availability verdict no longer render a tagged summary marker that could change once the verdict settles.