v0.5.0

[0.5.0] - 2026-06-30

A "make-it-loud" release: every fix turns a silent degradation into a loud
diagnostic through the existing channel, plus a packaging hardening and a
DAG-compaction feature — surfaced by dogfooding the framework on real apps, and
hardened by an adversarial review pass.

Added

• @czap/core — receipt-DAG compaction. DAG.checkpoint(dag, { below }) +
  DAG.spliceCheckpoint reclaim a long-lived receipt DAG's dominated prefix into
  a content-addressed checkpoint attestation (drop-only; the spliced DAG equals a
  fresh reload). Receipt.validateChain gains ChainValidationOptions { base, checkpoint } for cross-boundary validation (a compacted tail is verifiable only
  against its checkpoint). See ADR-0026.
• @czap/web — SSE overflow policy. SSEConfig.overflow
  (drop-newest | drop-oldest | coalesce-by-id, default coalesce-by-id) + an
  enriched BackpressureHint (policy / droppedCount / coalescedCount) + a
  stateChanges edge stream. See ADR-0005 (SSE addendum).
• create-liteship now scaffolds effect (^4.0.0-beta.32), fixing an
  unmet peer on a fresh project.

Fixed

• client:gpu warns once (canvas-default-size) when its host has no layout
  at boot and the canvas falls back to the 300×150 default — previously a silent
  tiny render.
• Signal directives warn once when a boundary input is recognized but has no
  live producer on that surface (signal-input-unserved-here) — previously a
  silent freeze; the uniform-signal "likely a typo" mislabel is split into two
  disjoint codes.
• @czap/genui rejects an unsupported registered handler prop (on* ≠
  onClick, or a non-string onClick) at validation instead of silently dropping
  it at render.
• @czap/web SSE no longer silently drop-newests under saturation (see
  Added), and the heartbeat watchdog now reconnects on timeout.
• client:stream / client:llm now run on the hardened SSE.create
  connection (unified reconnect/resumption + the heartbeat reconnect fix),
  processing each message synchronously in the dispatch turn with clean teardown
  (dispose / VT-swap single-boot); client:llm terminal frames close the live
  connection.

Changed

• effect peer range capped to >=4.0.0-beta.32 <5 across all @czap/*
  packages (was an unbounded >=4.0.0-beta.0), pinned by pnpm.overrides.effect
  and a drift guard.

Security

• Receipt.validateChainDetailed now requires a verified checkpoint to
  validate a compacted tail; a base watermark alone is rejected
  (checkpoint_invalid) — previously a truncated chain could validate with no
  proof of compaction.

Internal

• Cell↔DOM boundary committed as a guarded law (ADR-0027). Audit consumer-mode
  disallowed-edge coverage. Fixed two Effect-beta issues uncovered during review
  (Scope.use finalizing immediately; an overflow-buffer CPU spin). api-surface
  snapshot regenerated for the new exports.

Breaking

• @czap/genui renderFromCatalog now returns a tagged
  RenderFromCatalogResult ({ ok } union) instead of boolean. Callers using
  if (renderFromCatalog(...)) must switch to .ok.