inbound-antispam-panel: filter lists, written as rspamd maps

Step 5/12 of docs/plans/inbound-antispam-panel.md.

Store: AddSpamListEntry, ListSpamListEntries, DeleteSpamListEntry.
internal/inbound/lists.go validates and normalises an entry - sender
address, sender domain, client address or network (canonical text, an
IPv4-mapped address as IPv4, /0 refused) - and writes the lists as six
map files under /data/antispam (ANTISPAM_DIR), each atomically, 0644 in
a 0755 directory: the filter is another user in another container. All
six are written on every change and on every start with the relay on,
empty ones included. An entry whose maps could not be written is taken
back out of the table. The writer refuses a stored value with
whitespace, a newline or # in it.

The plan's allow.map / deny.map became one file per list and entry
type: to rspamd an IP map and a sender map are different map types.

deploy/antispam/rspamd/multimap.conf holds the rules; the fragment
mounts it and ./data/antispam into the sidecar. Deny is a prefilter
reject, allow a symbol weighing -100. Tried in a throwaway rspamd 3.11
container on the test server:
  - with allow as a prefilter accept, an address on both lists was
    accepted and an IP on both was refused - the rule that ran first
    decided; with the weight, deny won in all five mixed cases;
  - IPv4, IPv6, address (any case), domain (not its subdomains) match;
  - a rewritten file is reread in about ten seconds, no restart;
  - files that appear after rspamd started are loaded the same way.

No page edits the lists yet (step 6).

Checked on the test server, uncommitted tree: go vet ./... ok,
go test ./... ok (22 packages), make e2e ok - with the relay on
/data/antispam is 755 and holds the six maps, 644, empty.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture.md

@@ -102,6 +102,18 @@ smtp/inet` removes Debian's stock smtpd). Outbound delivery still uses the
   journal is pruned every six hours: rows
   older than the `inbound_spam_log_retention_days` setting, then down to
   10 000.
+  **Filter lists** (`inbound_spam_list`): allow and deny entries for the
+  external filter - sender address, sender domain, client address or network -
+  validated and normalised by `internal/inbound` (`lists.go`) and written as
+  six map files under `/data/antispam/` (`ANTISPAM_DIR`), each atomically, on
+  every change and on every start with the relay on. SelfPost never consults
+  them. The sidecar mounts the directory and rspamd's multimap rules
+  ([deploy/antispam/rspamd/multimap.conf](../deploy/antispam/rspamd/multimap.conf))
+  read them: a deny entry is a prefilter `reject`, an allow entry a symbol
+  weighing -100. Allow is deliberately not a prefilter `accept`: with two
+  prefilters rspamd lets the one that ran first decide, and deny then won or
+  lost by rule order (seen on rspamd 3.11). A refusal by the deny list
+  overrides any score, so deny wins whichever entries match.
   **Inbound relay** (`INBOUND_RELAY_ENABLE=true`): accepts only
   `relay_domains` + `relay_recipient_maps` (`reject_unauth_destination`,
   `reject_unlisted_recipient`). Maps under `/data/postfix/` (`relay_domains`,

docs/guide.md

@@ -851,6 +851,19 @@ with the message, and the upstream receives them with the mail. Copy the
 `antispam/rspamd/` directory next to the fragment; without the file accepted
 mail is still recorded, with no verdict.
 
+The same directory holds
+[multimap.conf](../deploy/antispam/rspamd/multimap.conf), the rules for the
+**allow and deny lists** kept in the panel. SelfPost does not apply the lists
+itself: it writes them as six files under `data/antispam/` (`allow_ip.map`,
+`allow_from.map`, `allow_domain.map` and the three `deny_` ones), the fragment
+mounts that directory into the sidecar, and rspamd rereads a file within
+seconds of a change - no restart. An entry is a sender address, a sender
+domain (that domain, not its subdomains) or a client address or network. A
+denied sender is refused outright. An allowed one is given a weight that no
+spam score outweighs, so it is accepted - unless a deny entry matches the same
+message: **deny wins**, whichever entries they are. The files are readable by
+anyone on the host; they hold addresses, not secrets.
+
 The panel only reports this setting; it does not change it. Every inbound
 domain page has a **Spam filter** box — on or off, what happens to mail while
 the filter is down, and that the filter belongs to the server, not to the

docs/plans/inbound-antispam-panel.md

@@ -102,13 +102,13 @@ Mirror send-log retention:
 | Entry types | sender address, sender domain (`@domain` suffix), client IP / CIDR |
 | Precedence | **deny overrides allow** |
 | Scope | instance-wide (not per inbound domain in v1) |
-| Where applied | **rspamd map files** under `/data/antispam/` (allow.map, deny.map); documented compose fragment mounts them into the sidecar |
+| Where applied | **rspamd map files** under `/data/antispam/`, one per list and entry type (`allow_ip.map`, `allow_from.map`, `allow_domain.map`, `deny_…`) - an IP map and a sender map are different map types to rspamd; documented compose fragment mounts them into the sidecar. Deny is a prefilter reject, allow a weight of -100 (as built: two prefilters do not give "deny overrides allow") |
 | SelfPost pre-check | **out of v1** — lists live in rspamd only |
 | Edit access | global administrator only |
 | When inactive | lists editable in the panel but UI warns that sync applies only when `INBOUND_ANTISPAM_MILTER` is set; `postfix reload` / rspamd reload documented in guide |
 
-List change → atomic map rewrite (same pattern as Postfix maps) → rspamd reload
-via documented operator step or sidecar `SIGHUP` in the compose fragment.
+List change → atomic map rewrite (same pattern as Postfix maps). No reload:
+rspamd rereads a changed map file by itself (about ten seconds on 3.11).
 
 ### Activation
 
@@ -247,7 +247,7 @@ Target version cut: **`2.1.0`** (MINOR), after `2.0.0`. One commit per step;
 - [x] Migration `0002_inbound_spam_log.sql` on the 2.0 baseline — **Composer**
 - [x] Inbound journal-milter + Postfix wiring — **Composer**
 - [x] mail.log tailer: inbound reject rows — **Composer**
-- [ ] List CRUD + validation + atomic rspamd map sync — **Composer**
+- [x] List CRUD + validation + atomic rspamd map sync — **Composer**
 - [ ] Panel: Inbound › Log and Inbound › Filter lists from the kit partials, mockups `in-log` / `in-filter-lists` (add client IP and engine columns mockup-first), evidence pairs — **Composer**
 - [ ] Backup includes `/data/antispam/` — **Composer**
 - [ ] Unit + handler tests — **Composer**

docs/roadmap.md

@@ -30,7 +30,7 @@ in `git log` and [CHANGELOG.md](../CHANGELOG.md).
 |---|---|---|---|---|
 | preflight | Installation check page (`/preflight`) | candidate | — | [plans/preflight.md](plans/preflight.md) |
 | contributing | `CONTRIBUTING.md` | candidate | — | — |
-| inbound-antispam-panel | Inbound antispam journal + allow/deny lists | in progress | 4/12 | [plans/inbound-antispam-panel.md](plans/inbound-antispam-panel.md) |
+| inbound-antispam-panel | Inbound antispam journal + allow/deny lists | in progress | 5/12 | [plans/inbound-antispam-panel.md](plans/inbound-antispam-panel.md) |
 | inbound-quarantine | Inbound spam quarantine (hold / review / release) | candidate | — | [plans/inbound-quarantine.md](plans/inbound-quarantine.md) |
 | csrf-tokens | Per-session CSRF tokens on state-changing forms | candidate | — | — |
 | template-data-typing | Typed structs for template data instead of `map[string]any` | candidate | — | — |