fix(evidence): retain completed observations on late cancellation

Validate completed reports before cancellation projection, retain valid
Evidence and captured command diagnostics, and convert raw cleanup partials
at their application owner. Record partial Evidence consistently across MCP
handlers. Keep page inspection separate from unfinished bundle analysis.

Refs #4261

src/application/WebNetworkCaptureService.test.ts

@@ -4,6 +4,10 @@ import { historicalHar } from "../../tests/fixtures/historicalHar.js";
 import { ok } from "../domain/result.js";
 import { projectAnalysisError } from "../domain/analysisErrorProjection.js";
 import { parseEvidence } from "../domain/evidence.js";
+import {
+  AnalysisCancelledError,
+  AnalysisOutputError,
+} from "../domain/analysisErrorCore.js";
 import {
   webNetworkCaptureSchema,
   type WebNetworkCapture,
@@ -125,6 +129,43 @@ it("rejects an adapter omitting its original observed digest before caller proje
   if (!result.ok) expect(result.error._tag).toBe("AnalysisOutputError");
 });
 
+it("retains valid completed capture Evidence on late cancellation and preserves invalid output", async () => {
+  const controller = new AbortController();
+  const report = fixture();
+  const late = await new WebNetworkCaptureService({
+    inspect: () => {
+      controller.abort();
+      return Promise.resolve(ok(report));
+    },
+  }).inspect(
+    { capture_path: report.artifact.path, format: "har" },
+    { signal: controller.signal },
+  );
+  expect(late.ok).toBe(false);
+  if (!late.ok) {
+    expect(late.error).toBeInstanceOf(AnalysisCancelledError);
+    expect(parseEvidence(late.error.partialObservation)).toMatchObject({
+      operation: "inspect_web_network_capture",
+      normalized_result: expect.objectContaining({ total_records: 1 }),
+    });
+  }
+
+  const malformed = fixture();
+  malformed.artifact.path = "/other.har";
+  const outputController = new AbortController();
+  const invalid = await new WebNetworkCaptureService({
+    inspect: () => {
+      outputController.abort();
+      return Promise.resolve(ok(malformed));
+    },
+  }).inspect(
+    { capture_path: "/capture.har", format: "har" },
+    { signal: outputController.signal },
+  );
+  expect(invalid.ok).toBe(false);
+  if (!invalid.ok) expect(invalid.error).toBeInstanceOf(AnalysisOutputError);
+});
+
 it.each([
   ["producer"],
   ["artifact"],