Add edit render manifest

docs/cinematic-video-editing-service-plan.md

@@ -800,7 +800,7 @@ It writes the script only and requires an imported audio file.
 17. [x] Add simple segment rendering without transitions.
 18. [x] Add concat-based final timeline rendering.
 19. [x] Add music and voiceover audio mixing.
-20. [ ] Add render manifest with command metadata and output details.
+20. [x] Add render manifest with command metadata and output details.
 21. [ ] Add basic transition support: cut, crossfade, fade in, fade out.
 22. [ ] Add SFX cue support.
 23. [ ] Add optional generated voiceover adapter interface.

src/main/java/org/example/videoclips/editing/FfmpegEditRenderer.java

@@ -14,6 +14,7 @@ import java.nio.file.StandardCopyOption;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.time.Instant;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
@@ -52,27 +53,33 @@ public class FfmpegEditRenderer implements EditRenderer {
         createDirectory(work);
         Map<String, ClipAnalysis> clips = analysis.clips().stream()
                 .collect(Collectors.toMap(ClipAnalysis::clipId, Function.identity()));
+        List<List<String>> commands = new ArrayList<>();
         List<Path> segments = new ArrayList<>();
         for (int index = 0; index < plan.decisions().size(); index++) {
             EditDecision decision = plan.decisions().get(index);
             Path output = work.resolve("segment_%04d.mp4".formatted(index + 1));
-            run(segmentCommand(clips.get(decision.clipId()).sourcePath(), decision, output));
+            runAndRecord(segmentCommand(clips.get(decision.clipId()).sourcePath(), decision, output), commands);
             segments.add(output);
         }
         Path concatFile = work.resolve("concat.txt");
         writeConcatFile(concatFile, segments);
         Path timeline = work.resolve("timeline-video.mp4");
-        run(concatCommand(concatFile, timeline));
+        runAndRecord(concatCommand(concatFile, timeline), commands);
         Path output = store.projectDirectory(projectId).resolve("final.mp4");
         Path audioDirectory = store.projectDirectory(projectId).resolve("audio");
         Path music = audioDirectory.resolve("music.wav");
         Path voiceover = audioDirectory.resolve("voiceover.wav");
         if (Files.isRegularFile(music) || Files.isRegularFile(voiceover)) {
-            run(audioMixCommand(timeline, Files.isRegularFile(music) ? music : null,
-                    Files.isRegularFile(voiceover) ? voiceover : null, output));
+            runAndRecord(audioMixCommand(timeline, Files.isRegularFile(music) ? music : null,
+                    Files.isRegularFile(voiceover) ? voiceover : null, output), commands);
         } else {
             copy(timeline, output);
         }
+        double duration = plan.decisions().getLast().timelineEndSeconds();
+        RenderManifest manifest = new RenderManifest(projectId,
+                plan.decisions().stream().map(EditDecision::clipId).toList(), output.toString(), duration,
+                List.copyOf(commands), Instant.now());
+        store.writeJson(projectId, "render-manifest.json", manifest);
         projectService.updateProject(projectId, EditProjectStatus.RENDERED, Path.of(project.inputDirectory()), null);
     }
 
@@ -165,6 +172,11 @@ public class FfmpegEditRenderer implements EditRenderer {
         }
     }
 
+    private void runAndRecord(List<String> command, List<List<String>> commands) {
+        run(command);
+        commands.add(command);
+    }
+
     private static ProcessResult execute(List<String> command) throws IOException, InterruptedException {
         Process process = new ProcessBuilder(command).redirectErrorStream(true).start();
         String output = new String(process.getInputStream().readAllBytes(), StandardCharsets.UTF_8);

src/main/java/org/example/videoclips/editing/RenderManifest.java

@@ -0,0 +1,14 @@
+package org.example.videoclips.editing;
+
+import java.time.Instant;
+import java.util.List;
+
+public record RenderManifest(
+        String projectId,
+        List<String> clipIds,
+        String outputPath,
+        double durationSeconds,
+        List<List<String>> commands,
+        Instant completedAt
+) {
+}

src/test/java/org/example/videoclips/editing/RenderManifestTest.java

@@ -0,0 +1,25 @@
+package org.example.videoclips.editing;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class RenderManifestTest {
+
+    @Test
+    void roundTripsRenderProvenanceAsJson() throws Exception {
+        ObjectMapper mapper = new ObjectMapper().findAndRegisterModules();
+        RenderManifest manifest = new RenderManifest("project", List.of("clip-1", "clip-2"), "final.mp4", 8.0,
+                List.of(List.of("ffmpeg", "-i", "clip.mp4", "final.mp4")),
+                Instant.parse("2026-07-10T10:00:00Z"));
+
+        String json = mapper.writeValueAsString(manifest);
+
+        assertThat(json).contains("\"clipIds\"").contains("\"commands\"").contains("final.mp4");
+        assertThat(mapper.readValue(json, RenderManifest.class)).isEqualTo(manifest);
+    }
+}