chore(release): bump sdk to 2.0.0 - #706

Bumps aws-durable-execution-sdk-python from 1.8.0 (unreleased; last published release is 1.7.0) to 2.0.0, and aligns every reference to the never-published 1.8.0: conformance test exact pins, the otel and insight SDK floors (both build against the 2.0 plugin interface), the test-pypi-otel hatch env, and the lambda-layer sdk-version pin. SDK-only release: otel and testing package versions are unchanged.

The migration guide covers every change below (merged in #655).

Changes since sdk-v1.7.0

Breaking Changes

• Typed per-operation error hierarchy; CallableRuntimeError, UserlandError, CallableRuntimeErrorSerializableDetails removed (136976d, feat(errors): typed per-operation error hierarchy #540)
• Graded callback errors; CallbackError out of the termination tree (c089f9f, feat(errors): Add graded callback error types #563)
• Serdes failures raise SerDesError instead of ExecutionError; first-run serialize/deserialize round trip for step, child contexts, map/parallel, and wait_for_condition; RetryableSerDesError added (d527f19 fix(step): Return round-tripped result on first run #543, caa57ad fix: round-trip serdes result on first run across ops #550)
• map/parallel: max_concurrency bounds in-flight branches, config validation at construction and call time, all_completed() now tolerates all failures, BatchResult.all omits never-started branches, summary payloads use an SDK-owned envelope (fdc952b)
• Replay validates operation identity (type, sub_type, name, parent_id); mismatches raise NonDeterministicExecutionError (38d94dc, fix(core): validate replay operation identity #698)
• wait_for_condition raises WaitForConditionError on exhaustion; WaitDecision and WaitStrategyConfig.timeout removed (e77a53e)
• wait_for_condition fails on unreadable polling state instead of restarting from initial_state (c183ec8)
• InvokeConfig.timeout / timeout_seconds removed (a982efa, fix: remove timeout from Invoke Config #340)
• Removed 1.x-only names: ItemBatcher, ItemsPerBatchUnit, BatchedInput, TerminationMode, StepFuture, MapConfig.item_batcher, ChildConfig.item_serdes, ChainedInvoke* enums (6a89b70)

Features

• should_complete custom completion predicate for map/parallel, with complete_batch/continue_batch, CompletionOutcome, CompletionStatus, and BatchCompletionError (d4090f1, feat: add should_complete to CompletionConfig #605)
• attempt exposed on StepContext and WaitForConditionCheckContext (6aa6a02, feat: expose operation attempt in contexts #549)
• Plugin auto-discovery and PluginLoadError (808e9a8, feat: auto-discover instrumentation plugins #620); plugin interface stabilization (c93073f, feat(plugin): stabilize plugin interface and otel package #625) — interface remains experimental

Bug Fixes

• Empty-string payloads preserved when serializing (b448f3e, fix: keep empty string payloads when serializing #555)
• Orphan checkpoint race rejected (ae73e73, fix: reject orphan checkpoint race #690)
• Missing checkpoint token from service handled (432cf07, fix: handle missing checkpoint token from service #571)

Docs

• 1.x to 2.0 migration guide (Docs/migration 1x to 2x #655)

Release checklist context (RELEASING.md)

• Version bumped in __about__.py
• Conformance test pins moved to ==2.0.0; otel/insight/dev-env floors to >=2.0.0; layer pin to 2.0.0
• After merge: create GitHub Release with tag sdk-v2.0.0 to trigger PyPI publish
• Note: a future testing package release should tighten its SDK floor (currently >=1.0.0), since published testing 1.x accepts SDK 2.0.0 where removed 1.x names no longer exist.