Add reproducible randomized test order

docs/execution-pipeline.mdmodified+6-2

Changes to docs/execution-pipeline.md

		⋯33 linesShow the 33 lines above this hunk@@ -34,6 +34,9 @@ reporters, including the configured JUnit output path.
34	34	child process.
35	35	- Every logical result owns ordered attempt history. A failure followed by a
36	36	successful retry is classified as `flaky`, distinct from an ordinary pass.
	37	+- Optional randomized execution uses one run seed across the selected plan.
	38	+ The seed is carried by reporters and `TestResults`; see
	39	+ [Randomized test order](randomized-order.md) for mode-specific guarantees.
37	40	- Summaries always come from `TestResults`, rather than executor-local counters.
38	41
39	42	## Extension points
		⋯13 linesShow the 13 lines above this hunk@@ -53,10 +56,11 @@ model without coupling the execution API to JSON.
53	56	Existing programmatic APIs remain source compatible:
54	57
55	58	- `TestRunner.init`, `runTests`, and `runTestsWithOptions` are unchanged.
56		-- `RunnerOptions` gains optional reporter, timeout, retry, repeat, and flaky-exit
	59	+- `RunnerOptions` gains optional reporter, timeout, retry, repeat, flaky-exit,
	60	+ shuffle, and seed
57	61	fields with backward-compatible defaults.
58	62	- `runDiscoveredTests` and `LoaderOptions` remain available; optional reporter,
59		- JUnit path, timeout, retry, repeat, flaky-exit, and writer fields default to
	63	+ JUnit path, timeout, retry, repeat, flaky-exit, shuffle, seed, and writer fields default to
60	64	the previous spec behavior.
61	65
62	66	CLI hosts can inject a stdout writer with `reporter_writer`. Embedded callers