fix(6253): the moment-proposal queue lists a signal pair only once it has proposed

pending() listed every suggested signal row, including pairs still gathering
evidence below the three-situation bar, so the queue held 200 "proposals"
where about 25 had crossed it. A signal pair now needs proposed_at in its
evidence, the same test the misfire half already applies; proposals from a
pass are unchanged.

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

src/grimoire/services/rule_moment_judgments.py

@@ -43,7 +43,7 @@ from __future__ import annotations
 import logging
 from datetime import datetime, timezone
 
-from sqlalchemy import exists, func, not_, select
+from sqlalchemy import exists, func, not_, or_, select
 from sqlalchemy.exc import IntegrityError
 
 from grimoire.models import async_session
@@ -274,6 +274,11 @@ async def pending(user_id: int, rule_id: int | None = None, limit: int = 200) ->
 
     Each rule carries what it is mounted on now, so a proposal is read beside
     the mounts it would add to.
+
+    A signal pair is a proposal only once it has crossed the bar and asked
+    (`proposed_at` in its evidence). Below the bar it is a row gathering
+    evidence, and listing it would bury the few pairs the signal stands
+    behind under every rule that was once opened after a moment.
     """
     from grimoire.services.rulebooks import _owned_rules_clause
 
@@ -282,7 +287,13 @@ async def pending(user_id: int, rule_id: int | None = None, limit: int = 200) ->
         stmt = (
             select(RuleMomentJudgment, Rule)
             .join(Rule, Rule.id == RuleMomentJudgment.rule_id)
-            .where(RuleMomentJudgment.state == SUGGESTED, _owned_rules_clause(user_id))
+            .where(
+                RuleMomentJudgment.state == SUGGESTED, _owned_rules_clause(user_id),
+                or_(
+                    RuleMomentJudgment.source != "signal",
+                    RuleMomentJudgment.evidence["proposed_at"].astext.isnot(None),
+                ),
+            )
         )
         if rule_id:
             stmt = stmt.where(Rule.id == int(rule_id))