Expose structured observation for async jobs

[abrady]

Summary

• accept an optional per-job reportFile for inline, file-backed, registered, and batched async scripts
• ingest JSONL progress, log, and output events without requiring Daz's main thread
• expose a bounded observation record through request status, result, and list responses
• add matching report_file= support to the synchronous and asynchronous dazpy clients
• prevent path aliases from letting a report file overwrite its submitted script file

Dependency chain

• Rebased onto current master / dazpy 2.9.2, including dazpy script-call batching + find_skeleton race fix #39's script-call batching and find_skeleton() retry.
• Built on Add async script-file jobs #36, which is already merged and supplies asynchronous script-file jobs.
• This is the first of two prerequisites for Make Daz MCP compact and dazpy-backed daz-mcp-server#9.
• Unify dazpy protocol operations #38 is stacked on this PR and supplies the unified dazpy protocol surface required by MCP [Refactoring] Phase 7: Settings Management System #9.
• MCP [Refactoring] Phase 7: Settings Management System #9 should not be accepted against a nightly until both Expose structured observation for async jobs #37 and Unify dazpy protocol operations #38 are present.
• The current nightly-69 / dazpy 2.9.1 artifact does not contain this change.

Validation

• 736 passed, 30 subtests passed across tests/test_dazpy.py and tests/test_dazpy_aio.py
• Studio 6 Release plugin compiled successfully with INSTALL_TO_DAZ=OFF; no DLL was installed and Daz was not restarted
• git diff --check and Python compileall passed

Live acceptance of the rebased DLL is intentionally deferred until the whole dependency stack is available in a published nightly.