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>

src/scribe/mcp/server.py

@@ -159,6 +159,10 @@ _READ_ONLY_TOOLS = frozenset({
     # retrieval_telemetry's reason, and needed by a read key so that a line
     # naming a moment can be understood by whoever was shown it.
     "list_moments",
+    # The pass over the corpus and its queue (milestone 458 step 7): which
+    # rules are unjudged and which proposals wait. Reads of the caller's own
+    # rules, as list_rules is.
+    "rules_to_mount", "rule_moment_proposals",
 })
 
 # Every tool that WRITES, by name. Nothing reads this set at runtime — a tool
@@ -210,6 +214,9 @@ _WRITE_TOOLS = frozenset({
     # Which actions reach which moment on this install (milestone 458). Each
     # changes what fires for every later session, so a read key is refused.
     "map_action", "unmap_action",
+    # Proposing moments for a rule writes a judgment row; judging one mounts
+    # or unmounts the rule (step 7).
+    "propose_rule_moments", "judge_rule_moments",
     # A reviewer's verdicts on logged menu lines (#4772) — rows carrying free
     # prose the agent authored, `rule_outcome`'s reason for being a write.
     "judge_menu",