Replay can leave post-condition activity history unconsumed after signals and updates

[rmcdaniel]

User-visible defect\n\nA signal or applied update accepted after a condition has resolved, while the workflow's successor activity is running, can retain the completed condition's workflow sequence. Cold replay currently falls back to that stale sequence after an intervening activity boundary and binds the receiver to the already-completed condition.\n\nThe completed condition will not drain receivers recorded after its terminal event. The workflow therefore reaches its next condition with stale state and remains waiting even though the durable history contains the accepted receivers and the successor activity completion.\n\n## Reproduction\n\n1. Open and satisfy condition A with a signal.\n2. Schedule activity B.\n3. While B is running, accept an update and another signal whose recorded workflow sequence still references condition A.\n4. Complete B.\n5. Replay from the full history into a condition that depends on the update and second signal.\n\nCurrent result: replay emits another condition wait.\n\nRequired result: replay applies the post-boundary receivers at their ordinary activity boundary, consumes B's durable result, and completes.\n\n## Acceptance\n\n- Treat recorded event position as authoritative once an activity, timer, child, or terminal step separates a receiver from an earlier condition, even when the receiver carries that condition's stale sequence.\n- Cover both SignalReceived and UpdateApplied in a cold-replay regression with post-condition activity history.\n- Preserve explicit selected-condition sequence binding and repeated physical wait behavior.\n- Pass the complete non-integration suite and static checks.

[rmcdaniel]

Implemented, published, and independently verified.

Root cause: a receiver that followed a durable step could keep an explicit stale condition sequence when no active wait existed. Replay then reused the prior completed condition binding and could leave later activity history unconsumed.

Fix and evidence:

• Source fix: Keep post-condition receivers on their replay boundary #51 (0833b3ce3257ea3fe8c3c5c36a2e984f19770887)
• Added signal and update replay regressions plus a static Avro replay-corpus fixture
• Focused replay suite: 69 passed
• Full non-integration suite: 1,302 passed, 2 skipped
• Source PR CI, Server integration, regression corpus, packaging, and target-branch qualification all passed
• Release preparation: Release Python SDK 2.0.1 #52 (eccc4ca9bea566e553fb0850ab6ea8b7cb742b71)
• Public release: Python SDK 2.0.1
• Public PyPI exact and default resolution select durable-workflow 2.0.1; a clean environment installed and imported durable-workflow==2.0.1 successfully
• The post-upload audit exposed an unrelated assertion that rejected the intentionally yanked historical 0.1.0 package. Allow intentional historical PyPI yanks #53 repaired that invariant, passed the full CI matrix and live PyPI audit, and is merged.

The acceptance boundary is satisfied: post-condition signal/update receivers remain on their correct replay boundary, subsequent activity history is consumed, and the fix is available through the default stable Python package channel.