Report decisions-based mailing list routing

The prompts used to arrive at this change since the previous commit

User asked to read decisions.json as an indicator for mailing-list handling, route choice h to appropriate functional mailboxes, route choice a under Afmelden, combine lists from the same person or organization, first draw up a report, then create a plan to add the structure to the existing approach.

Any special observations that may be relevant for version management for this version. Be brief.

This is a planning/report commit only. No sorter behavior changed; verplaats_bestaand.py still uses mail_routes.py and does not yet read decisions.json or a generated mailing-list policy.

restart_prompt.md

@@ -153,6 +153,16 @@ Latest live mailbox verification:
 
 The prior script review is in `reports/script_review_findings.md`.
 
+The decisions-based mailing-list routing proposal is in `reports/decisions_mailinglist_routing_report.md`.
+
+That report interprets `decisions.json` as advisory intent:
+
+- `keuze: "h"` means keep and route to an appropriate functional mailbox.
+- `keuze: "a"` means route below `INBOX.Afmelden.*` for unsubscribe/review.
+- `keuze: "s"` is ambiguous and should be confirmed before automation.
+- Obvious aliases from the same sender or organization should be combined, including Coursera, MIT Technology Review, Eva Keiffenheim/Substack, PostNL, STRATO, Forte Labs, CIONET, Gusti, Nord, Proton, Vonage/Nexmo, and Visme.
+- The report is not active code yet; `verplaats_bestaand.py` still routes through `mail_routes.py`.
+
 Key earlier findings:
 
 - The old redistribution script selected some source folders read-only and then tried to delete messages.