Skip application for sections without approved edits

docs/roadmap/remediation.md

@@ -707,6 +707,8 @@ decisions, and output order without rescanning decisions for each candidate.
 
 ## R20 — P3: Skip Apply-Time Copies for Sections With No Approved Edits
 
+**Status:** Completed. Sections without approved proposals retain their existing segments. The runner still records every work unit, and sections with approved changes use the existing ordered application and protection checks. No-edit coverage verifies transcript and work-unit results.
+
 **Category**
 
 Avoidable transcript copying during Stage 12 application.

internal/framework/runner/runner.go

@@ -254,6 +254,12 @@ func transcriptFromSections(sections []chunking.Section) *schema.Transcript {
 // applyWithinSections leaves section membership and initial metadata unchanged.
 // Approved proposals are applied only to their identified section.
 func applyWithinSections(sections []chunking.Section, approved []proposals.EnrichedCorrectionProposal, policy proposals.ReplacementPolicy, vocabulary validators.ProtectedVocabulary, allowRepetitionCleanup bool) ([]chunking.Section, []proposals.AppliedChange, []proposals.SkippedChange, []int, error) {
+	applied := make([]proposals.AppliedChange, 0)
+	skipped := make([]proposals.SkippedChange, 0)
+	appliedBySection := make([]int, len(sections))
+	if len(approved) == 0 {
+		return sections, applied, skipped, appliedBySection, nil
+	}
 	bySection := make(map[int][]proposals.EnrichedCorrectionProposal, len(sections))
 	known := make(map[int]struct{}, len(sections))
 	for _, section := range sections {
@@ -270,11 +276,12 @@ func applyWithinSections(sections []chunking.Section, approved []proposals.Enric
 	}
 	updated := make([]chunking.Section, len(sections))
 	copy(updated, sections)
-	applied := make([]proposals.AppliedChange, 0)
-	skipped := make([]proposals.SkippedChange, 0)
-	appliedBySection := make([]int, len(sections))
 	for i, section := range sections {
-		result := proposals.ApplyProposals(transcriptFromSection(section), bySection[section.Index], policy, func(before, after string) bool { return vocabulary.AllowsChange(before, after, allowRepetitionCleanup) })
+		candidates := bySection[section.Index]
+		if len(candidates) == 0 {
+			continue
+		}
+		result := proposals.ApplyProposals(transcriptFromSection(section), candidates, policy, func(before, after string) bool { return vocabulary.AllowsChange(before, after, allowRepetitionCleanup) })
 		updated[i].Segments = result.Transcript.Segments
 		applied = append(applied, result.Applied...)
 		skipped = append(skipped, result.Skipped...)

internal/framework/runner/runner_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"os"
 	"path/filepath"
+	"reflect"
 	"strconv"
 	"strings"
 	"sync"
@@ -396,6 +397,14 @@ func TestRunnerProposalsExecutePerChunkSection(t *testing.T) {
 	if len(out.ModuleResults) != 1 {
 		t.Fatalf("expected one module result, got %+v", out.ModuleResults)
 	}
+	if !reflect.DeepEqual(out.FinalTranscript, transcript) || len(out.WorkUnits) != 3 {
+		t.Fatalf("no-edit run changed the transcript or inventory: %+v", out)
+	}
+	for _, unit := range out.WorkUnits {
+		if unit.State != outcomes.WorkCompleted || unit.CorrectionsApplied != 0 {
+			t.Fatalf("no-edit section was not completed: %+v", unit)
+		}
+	}
 	if len(seenBySection) != 3 {
 		t.Fatalf("expected 3 chunked proposal calls, got %d", len(seenBySection))
 	}