feat(issue-5): report finalization manifest and side-effect evidence

The agent declares that its work is finished; the reader re-derives the hash
from the file rather than trusting the number in the declaration. A manifest the
watcher wrote itself would attest only that the watcher saw a stable file, which
is the self-certifying evidence shape rejected earlier in this issue.

Finalizing promotes a staged report by atomic rename before writing the
manifest, so a reader cannot observe a half-written report as final. Rewriting
the report afterwards invalidates the declaration immediately, because the
recomputed hash no longer matches -- a new body needs a new finalization.

A job that declared side effects must show evidence for every one of them.
Partial evidence is treated as none: the work is not known to be complete.

publish_event gains --finalize-report, --side-effect and --attempt-id, and does
the finalization before publishing. A `completed` event whose report is still
being written would invite exactly the partial adoption the contract forbids, so
a failure there fails the publish.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UrDNJkHmm18uu7n7JwV5Qd

.agents/skills/lib_py/delegation/publish_event.py

@@ -205,6 +205,15 @@ def main(argv=None) -> int:
                         help="force retain=True (auto for completed/error)")
     parser.add_argument("--registry-dir", default=DEFAULT_REGISTRY_DIR)
     parser.add_argument("--attempts", type=int, default=3)
+    parser.add_argument("--finalize-report", default=None, metavar="PATH",
+                        help="atomically finalize this report and declare its "
+                             "completion manifest before publishing")
+    parser.add_argument("--side-effect", action="append", default=[], dest="side_effects",
+                        metavar="KIND=REFERENCE",
+                        help="evidence for an external side effect this job performed")
+    parser.add_argument("--attempt-id", type=int, default=None,
+                        help="attempt this finalization belongs to (default: the "
+                             "job's current iteration)")
     parser.add_argument("-v", "--verbose", action="store_true")
     args = parser.parse_args(argv)
 
@@ -227,6 +236,33 @@ def main(argv=None) -> int:
         logger.error("no job to publish for (unknown --job or no pending job)")
         return 1
 
+    # Finalize before publishing: a `completed` event whose report is still being
+    # written would invite exactly the partial-report adoption the contract
+    # forbids. Failing here fails the publish, on purpose.
+    if args.finalize_report:
+        from lib_py.loop import finalize  # local import: optional dependency of this CLI
+
+        try:
+            side_effects = finalize.parse_side_effects(args.side_effects)
+        except ValueError as exc:
+            logger.error("%s", exc)
+            return 1
+        attempt_id = args.attempt_id
+        if attempt_id is None:
+            try:
+                attempt_id = load_job(job_id, args.registry_dir).get("iteration", 1)
+            except FileNotFoundError:
+                attempt_id = 1
+        try:
+            manifest = finalize.finalize_report(
+                args.finalize_report, job_id, attempt_id,
+                side_effects=side_effects, declared_by="agent")
+        except (OSError, FileNotFoundError) as exc:
+            logger.error("could not finalize report: %s", exc)
+            return 1
+        logger.info("finalized %s (sha256 %s...)", manifest["report_path"],
+                    manifest["sha256"][:12])
+
     try:
         prepared = prepare_event(
             job_id=job_id,