operonx 1.0.0 — state observability, HITL, back-edge loops, LLMOp structured mode

Milestone release: state observability, HITL primitives, LangGraph-style
back-edge loops, structured-output LLMOp, and cleanup of deprecated
surfaces. See MIGRATION.md for the upgrade recipe.

Added — Phase 1 (state)

• PARENT.declare(**vars, reducers={...}) — shared cells with optional
  fan-in reducers. Replaces PARENT.shared().
• operonx.reducers — add_messages (LangGraph-compatible id-upsert
  • RemoveMessage / REMOVE_ALL_MESSAGES sentinels), dict_merge,
    plus support for operator.add / operator.or_ from stdlib.

Added — Phase 2 (observability + HITL)

• Checkpointer protocol + InMemoryCheckpointer with per-step delta
  storage; get_state(step) folds, get_updates(step) returns delta,
  list_steps() enumerates. Zero overhead when no checkpointer bound.
• MemoryState._write_cell funnel + write-observer bus. All cell
  mutations (including SCRATCH[k] = v) flow through it.
• @op(exclude=..., include=..., observe_max=...) — filter observability
  at emission source. Polymorphic list-or-dict; mutual-exclusion of
  include/exclude. ObserveBudgetExceeded (inherits BaseException)
  as a circuit breaker for runaway generator ops.
• InterruptOp — HITL suspend/resume via asyncio.Future.
• EmitOp — fire-and-forget custom events.
• engine.stream(mode="updates" | "values" | "frames" | "custom") +
  engine.invoke() alias.

Added — Phase 3 (loops)

• Build-time cycle rewrite: write a back-edge inside @graph and the
  Phase 3 pass compiles it into a hidden _GraphLoop. LangGraph-style
  agent loops without the visible loop wrapper.
• @graph(strict_dag=True) opt-out for fail-fast on accidental cycles.

Added — LLMOp structured-output layer

• LLMOp.of(fields=..., parser=..., validators=..., max_retries=..., retry_hint=True) — inline parse + validate + error-guided semantic
  retry on the same resource (Instructor-style).
• LLMRefusalError and ValidatorError exception classes; refusal
  detected via finish_reason in {content_filter, safety} or
  non-empty extras.refusal (structural, not content-heuristic).
• operonx.providers.parsing — pure functions
  (parse_json / parse_xml / parse_yaml, ExtractField,
  extract_value_by_path, convert_type, apply_validators,
  parse_and_extract) for text-only parsing without an LLM call.

Changed

• Fallback trigger narrowed: fallback=[...] fires only on refusals,
  content-filter blocks, or exhausted transport (SDK-side). Parse /
  validator failures NO LONGER trigger fallback — they use
  max_retries on the same resource.
• Transport-level retries (429 / 5xx / timeout) are delegated to the
  underlying SDK; LLMOp does not add its own transport-retry knob to
  avoid double-retry surprises.

Removed (BREAKING)

• PARENT.shared(**vars) — use PARENT.declare(**vars).
• GraphOp.loop(name=..., until=..., **initial_state) constructor —
  use a back-edge inside @graph and let the rewrite synthesize the
  loop. The _GraphLoop type still exists internally.
• @graph(until=..., max_iterations=...) decorator surface — replaced
  by (a) back-edge for control-flow loops or (b) LLMOp(max_retries=N)
  for LLM parse/validate retry.
• ParserOp class + ParserType alias — parsing lives inline in
  LLMOp(fields=..., parser=..., validators=...); pure functions for
  standalone use are in operonx.providers.parsing.
• ask() helper (operonx.providers.ops.ask) — subsumed by
  LLMOp.of(fields=..., max_retries=...).

Fixed

• Shared-cell reducer degraded to LWW on nested-ctx writes (from
  Phase 3 loop iterations) — _write_cell now reads old via
  Cell.__getitem__ which handles the shared→DEFAULT_CONTEXT mapping.

v0.7.1

What's Changed

• ci: remove published-smoke workflow by @batman1m2001-cyber in #2
• v0.7.1 — generator dispatch fix, provider auto-register, scheduler precompute by @batman1m2001-cyber in #3

Full Changelog: v0.7.0...v0.7.1