docs + dev.sh: loop in README/REPORT, ./dev.sh loop runner, scan-failure exit codes

README gains the self-host loop section (flow diagram, config reference
rows for [loop]/[redmine.status_map]/[keyproxy]/[gitea], CLI flags,
status table); REPORT.md records phase 3a including the die list for the
bash stack it replaces. dev.sh grows a `loop` runner (repo bind-mounted,
key env passthrough). `harness loop --once` now exits 2 when the intake
scan itself fails so cron setups alert loudly; daemon mode still logs
and retries.

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

.gitignore

@@ -3,3 +3,4 @@ reports/
 bin/
 *.test
 .smoke/
+state/