mod: Ext 17 — per-domain policy registry, 364/364

mod/register-policy! domain rules + mod/decide-in domain r reports give each
rose-ash domain its own rule set; unregistered domains fall back to default-rules
(never unmoderated). Same spam report → remove under a strict market policy, hide
under blog default. Engine already took rules as a param, so this is registry +
fallback, no engine change. +14 tests.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/mod/tests/policies.sx

@@ -0,0 +1,112 @@
+;; lib/mod/tests/policies.sx — Ext 17: per-domain policy registry.
+
+(define mod-pol-count 0)
+(define mod-pol-pass 0)
+(define mod-pol-fail 0)
+(define mod-pol-failures (list))
+
+(define
+  mod-pol-test!
+  (fn
+    (name got expected)
+    (begin
+      (set! mod-pol-count (+ mod-pol-count 1))
+      (if
+        (= got expected)
+        (set! mod-pol-pass (+ mod-pol-pass 1))
+        (begin
+          (set! mod-pol-fail (+ mod-pol-fail 1))
+          (append!
+            mod-pol-failures
+            (str name "\n    expected: " expected "\n    got:      " got)))))))
+
+(mod/policies-reset!)
+
+;; market is strict: spam is removed outright, not just hidden
+(define
+  mod-pol-market-rules
+  (list
+    (mod/mk-rule
+      "market-spam-remove"
+      :remove (list (list :classification "spam")))
+    (mod/mk-rule "default-keep" :keep (list))))
+
+(mod-pol-test!
+  "unregistered domain falls back to default"
+  (mod/policy-registered? "market")
+  false)
+(mod/register-policy! "market" mod-pol-market-rules)
+(mod-pol-test!
+  "domain registered after register!"
+  (mod/policy-registered? "market")
+  true)
+
+(define mod-pol-spam (mod/mk-report "r1" "a" "b" "this is spam"))
+
+;; ── same report, different domain → different action ──
+
+(mod-pol-test!
+  "market policy removes spam"
+  (get (mod/decide-in "market" mod-pol-spam (list mod-pol-spam)) :action)
+  "remove")
+(mod-pol-test!
+  "market decision uses market rule"
+  (get (mod/decide-in "market" mod-pol-spam (list mod-pol-spam)) :rule)
+  "market-spam-remove")
+(mod-pol-test!
+  "blog (unregistered) uses default → hide"
+  (get (mod/decide-in "blog" mod-pol-spam (list mod-pol-spam)) :action)
+  "hide")
+(mod-pol-test!
+  "blog decision uses default rule"
+  (get (mod/decide-in "blog" mod-pol-spam (list mod-pol-spam)) :rule)
+  "spam-hide")
+
+;; ── policy-for resolution ──
+
+(mod-pol-test!
+  "policy-for market returns market rules"
+  (mod/policy-for "market")
+  mod-pol-market-rules)
+(mod-pol-test!
+  "policy-for unknown returns default"
+  (mod/policy-for "events")
+  mod/default-rules)
+(mod-pol-test!
+  "registered-domains lists market"
+  (mod/registered-domains)
+  (list "market"))
+
+;; ── a second domain ──
+
+(define
+  mod-pol-events-rules
+  (list (mod/mk-rule "events-keep-all" :keep (list))))
+
+(mod/register-policy! "events" mod-pol-events-rules)
+(mod-pol-test!
+  "events policy keeps everything (even spam)"
+  (get (mod/decide-in "events" mod-pol-spam (list mod-pol-spam)) :action)
+  "keep")
+(mod-pol-test!
+  "two domains registered"
+  (len (mod/registered-domains))
+  2)
+(mod-pol-test!
+  "market still removes after second registration"
+  (get (mod/decide-in "market" mod-pol-spam (list mod-pol-spam)) :action)
+  "remove")
+
+;; ── clean report is keep everywhere ──
+
+(define mod-pol-clean (mod/mk-report "r2" "a" "b" "a fine post"))
+(mod-pol-test!
+  "clean report keep in market"
+  (get (mod/decide-in "market" mod-pol-clean (list mod-pol-clean)) :action)
+  "keep")
+(mod-pol-test!
+  "clean report keep in blog"
+  (get (mod/decide-in "blog" mod-pol-clean (list mod-pol-clean)) :action)
+  "keep")
+
+(define mod-policies-tests-run! (fn () {:failures mod-pol-failures :total mod-pol-count :passed mod-pol-pass :failed mod-pol-fail}))