Reconstruct and merge ordered inputs without general sorting

docs/roadmap/remediation.md

@@ -1,6 +1,6 @@
 # Shared reporting and PromptKit adoption remediation
 
-Status: two open findings; R1–R5 complete. R1–R3 are from the architectural review of
+Status: one open finding; R1–R6 complete. R1–R3 are from the architectural review of
 `f83866e44a8a9066db52cbd2aa5cccde0d69a839`. R4–R7 are from the algorithmic
 audit of `f5b2d1f80c4720b762f3301c29d5050710c210d0`; R4 is a correctness
 issue and R5–R7 are efficiency opportunities for consideration.
@@ -243,6 +243,15 @@ threshold or benchmark is needed to establish the complexity difference.
 
 ## R6 — P3: Ordered inputs use general sorting of already indexed streams
 
+**Complete.** Initial preparation places ordered setters at parser positions
+and scans them once, using O(M+F) traversal and O(M) ordering storage. Captured
+replay uses a standard-library heap to merge K monotone streams in O(K+E log K)
+work for K greater than one, O(E) for one stream, and O(K) merge storage.
+Selection order breaks ties, preserving duplicate handles. Core regressions cover
+nested capture, reversed/subset/single/empty/duplicate selections, both replay
+methods, conversion counts, and repeated invocations. The independent core and
+aligned ckconfig/ckprompt suites pass with Go 1.27.0.
+
 **Location:** [binding.go](../../binding.go), prepareInputWithOccurrences line
 316, and [flag_values.go](../../flag_values.go), FlagValues.applyTo line 122.