feat(moments): mount the corpus by proposal - a pass and an open-after-moment signal, both stopping at the operator (milestone 458 step 7, #4925)

A rule written before moments existed is mounted on nothing. Step 7 records,
per (rule, moment), whether it belongs there and who said so:

- rule_moment_judgments (migration 0118, backup v23): suggested / confirmed /
  rejected, from a pass, the signal, or an edit. Moment "" is "no moment fits".
- The pass: rules_to_mount lists unjudged rules; propose_rule_moments records
  suggestions that mount nothing; rule_moment_proposals and
  judge_rule_moments put them to the operator. A confirm mounts, a reject is
  kept so the pair is never proposed again. Same service behind REST and a
  "Waiting on you" panel in Settings > Moments.
- Edits are judgments: set_rule_moments, the one mount write path, confirms
  what was added and rejects what was removed in the same transaction.
- The signal: scribe_moment.sh keeps a per-session acts ledger; when a rule
  is opened, scribe_record_opened.sh sends the last three minutes of it to
  /api/plugin/rule-opened. The acts resolve through the install's mappings;
  work.run and work.change are not evidence. Counted per distinct session
  with lesson_rules' evidence model, and once due the open returns one line
  asking the reader to offer the mount.
- scribe_session_end.sh removes the session's scribe-moment files.

Plugin 2026.10.05.2003.

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

alembic/versions/0118_rule_moment_judgments.py

@@ -0,0 +1,61 @@
+"""rule_moment_judgments — whether a rule belongs on a moment, and who said so
+(milestone 458 step 7, #4925)
+
+Revision ID: 0118
+Revises: 0117
+Create Date: 2026-10-05
+
+One row per (rule, moment) with a state: `suggested` while a proposal waits
+for a judgment, `confirmed` or `rejected` once one is made. The mount itself
+stays in rule_moments; this records the proposals that are not mounts yet and
+the rejections that must stop them being proposed again. Moment '' is "no
+moment fits this rule". CASCADE on the rule — a judgment about a rule that no
+longer exists says nothing. No backfill: the mounts made before this table
+were judgments too, but recording them now would invent who made them.
+"""
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+from alembic import op
+
+revision = "0118"
+down_revision = "0117"
+branch_labels = None
+depends_on = None
+
+# One place each, so the CHECKs and the model's JUDGMENT_STATES / SOURCES
+# cannot drift (rule 36: a new value later means DROP + ADD CONSTRAINT in the
+# same migration).
+_STATES = ("suggested", "confirmed", "rejected")
+_SOURCES = ("pass", "signal", "edit")
+
+
+def upgrade() -> None:
+    op.create_table(
+        "rule_moment_judgments",
+        sa.Column("id", sa.BigInteger(), primary_key=True),
+        sa.Column("rule_id", sa.BigInteger(), sa.ForeignKey("rules.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("moment", sa.Text(), nullable=False),
+        sa.Column("state", sa.Text(), nullable=False, server_default="suggested"),
+        sa.Column("source", sa.Text(), nullable=False, server_default="pass"),
+        sa.Column("note", sa.Text(), nullable=True),
+        sa.Column("evidence", postgresql.JSONB(), nullable=True),
+        sa.Column("judged_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.text("now()")),
+        sa.UniqueConstraint("rule_id", "moment", name="uq_rule_moment_judgments_pair"),
+    )
+    op.create_check_constraint(
+        "ck_rule_moment_judgments_state", "rule_moment_judgments",
+        "state IN (" + ", ".join(f"'{s}'" for s in _STATES) + ")",
+    )
+    op.create_check_constraint(
+        "ck_rule_moment_judgments_source", "rule_moment_judgments",
+        "source IN (" + ", ".join(f"'{s}'" for s in _SOURCES) + ")",
+    )
+    op.create_index("ix_rule_moment_judgments_rule_id", "rule_moment_judgments", ["rule_id"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_rule_moment_judgments_rule_id", table_name="rule_moment_judgments")
+    op.drop_constraint("ck_rule_moment_judgments_source", "rule_moment_judgments", type_="check")
+    op.drop_constraint("ck_rule_moment_judgments_state", "rule_moment_judgments", type_="check")
+    op.drop_table("rule_moment_judgments")