Fix v1.1.0 review findings: correctness, CI, telemetry, and tests

[thanos]

Address the issues identified in reviews/review-1.1.0.md so the streaming release is buildable, CI-green, and safe to tag. Focus is on correctness bugs, observability accuracy, producer behavior, documentation fixes, and regression coverage — not new features.
Correctness

• Fix Broadway chunk producer duplicate delivery (F-01): track remaining indices and advance by consumed count, not successful event count
• Handle Task.async_stream {:exit, reason} timeouts in concurrent streaming (F-02) instead of crashing with FunctionClauseError
• Guard empty/degenerate slice regions in slice_specs/3 (F-03)
• Emit reliable stream-stop telemetry in concurrent mode via with_stream_stop/4 (F-09)
• Validate write_stream entries and route invalid input through on_error (F-13)
• Raise ExZarr.StreamError on read halt; return {:error, ...} on write halt (F-26)
• Warn when deprecated :parallel is used without :concurrency (F-23) Producers and streing internals
• Stop GenStage/Broadway producers with :normal after exhaustion (F-08)
• Extract shared demand logic into ExZarr.Streaming.Producer (F-21/F-22)
• Deduplicate stream_chunks/stream_slices concurrency paths via stream_events/6
• GenStage facade accepts flat stream options or nested :stream_opts (F-12) Telemetry and docs
• Document :telemetry.span suffix events (:start/:stop/:exception) in ExZarr.Telemetry and guides/telemetry.md (F-04/F-07)
• Update release notes and cloud storage patterns with correct event names
• Fix broken cookbook/livebook examples (F-16)
• Correct Flow concurrency docs (F-11), write_stream durability claims (F-10), and stream_slices I/O notes (F-14/F-19)
• Tone down marketing language; remove session artifacts (F-25) Build and CI
• Pin zigler to ~> 0.16; bump CI Zig to 0.16.0 and run mix zig.get (F-06)
• Resolve ex_doc packaging constraint with zig_doc (F-05)
• Register v1.1 docs extras/groups in mix.exs (F-18)
• Add .tool-versions for Elixir 1.19.5 / OTP 28 / Zig 0.16.0 Tests
• Expand streaming_api_test.exs: timeouts, pipelines, telemetry, batch writes, on_error callbacks/halt, GenStage/Broadway/Flow integration (F-15)
• Add streaming_property_test.exs: chunk count math and write/read roundtrip properties (review items 9–10) New modules
• lib/ex_zarr/stream_error.ex
• lib/ex_zarr/streaming/producer.ex
• test/ex_zarr/streaming_property_test.exs

Description

Related Issues

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement
• Test improvement

Changes Made

Testing

• All existing tests pass
• Added new tests for new functionality
• Tested manually with:

  # Example usage

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published

Breaking Changes

None / N/A

Additional Notes