docs(website): §7.1 Q9 — core's own news.post emitter

`news.post` is a declared trigger with no caller: `coreTriggers.js` says so in
as many words, and Phase 6 migrated only the four `team.*` ones. A rule naming
it can never fire, so on a real deployment the only in-app or email items the
engine can produce today come from Teams. Phase 7 flagged it in passing; this
writes it down properly as an open question.

The substance is not the call — it is the three other things a news publish
already fires, and which of them the engine has any business replacing:

- the announce leg (`announce_job_legs`, `module-uo` owns `towncrier`) — a
  one-shot delivery to a channel of the deployment, with retry. NOT the
  engine's.
- a module's post hook (`registerPostHook`) — idempotent state mirroring that
  also runs on delete and refreshes on a silent edit. NOT the engine's.
- the raw `pushDispatch.publish('news.post', …)` — a per-person notification.
  THIS is the one that becomes an emit.

So modules keep both doors onto a news publish and neither changes. What a
module does not get is the ability to fire `news.post` itself — the id's owner
is core, `emit` binds the owner at the call, and §7.2's one namespace gives an
id exactly one owner across both facets. A module wanting its own person-facing
news notification declares its own trigger.

Three things to settle first, recorded rather than decided: continuity (the
emit replacing the tickle stops push silently until a rule is enabled — G22's
shape, and Phase 6 decision 3's), reusing the job-id transition signal rather
than re-deriving it, and which phase owns it. Recommended home: Phase 11, whose
title understates it — a pointer and an extra acceptance line land there too.

Code: RunicGateway/website#175

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

website/ENGAGEMENT.md

@@ -2764,7 +2764,10 @@ declared trigger that **nothing emits through the engine** — `coreTriggers.js`
 admin publish path still fires a raw `pushDispatch.publish` beside the engine rather than through it.
 The consequence for this phase: on a real deployment the only in-app items a rule can produce today
 come from the four Team triggers. Wiring the news emitter is a one-line `ctx.events.emit`-shaped change
-that belongs with whoever owns that decision, not smuggled into the channel's own phase.
+that belongs with whoever owns that decision, not smuggled into the channel's own phase. **Written up as
+§7.1 Q9**, which sets out the three other things a publish already fires (an announce leg, a module's
+post hook, the raw tickle), which of them the engine replaces and which it must not touch, and the
+continuity question that has to be answered before anyone writes the line. Recommended home: Phase 11.
 
 **Still later phases':** the app's inbox screen and the tickle → pull → inbox path (Phase 8), and the
 suppression list, which this channel has no equivalent of — there is no address to suppress.
@@ -2827,10 +2830,19 @@ starts early and lands independently.
 with Phase 6 if Phase 10 is still in flight — the trigger simply omits `nextStage`/`estimatedCollapse`
 until the v5 overlay is deployed, which the `required: false` declaration already permits.
 
+**Also core's own `news.post` emitter, which this phase's title understates** (§7.1 Q9). `news.post` is
+declared with no caller, so a rule naming it can never fire; wiring it is one `ctx.events.emit`-shaped
+call in `announceIfNewlyPublished`, gated on the same job-id transition signal the push already uses.
+**The announce legs and the post hooks are untouched** — a module's town-crier leg is a delivery to a
+channel of the deployment and its news-gump hook is state mirroring, neither of which is a per-person
+notification. What the emit replaces is the raw `pushDispatch.publish` beside them, and Q9's continuity
+question has to be answered before it does.
+
 **Acceptance:** the five-rung shard visibility walk still shows no leak; a house transitioning to
 `Greatly` on the live rig produces one email to the linked owner and nothing to anyone else; a second
 transition inside the cooldown produces nothing; a refresh back to `LikeNew` inside the delay window
-cancels the pending mail.
+cancels the pending mail; **a news post published on the rig reaches a rule, and the town-crier leg and
+every registered post hook still fire exactly as they did.**
 **Guardrails:** `check:modules` proves core gained no UO identifier across every phase to this point.
 
 ---
@@ -2963,7 +2975,7 @@ day it ships.
 
 ## Part 7 — Open questions and forward-compat notes
 
-### 7.1 Questions for the org lead — seven answered, one still open
+### 7.1 Questions for the org lead — seven answered, two still open
 
 1. ✅ **ANSWERED — may unverified addresses receive engagement mail?** *"Emails need to be unique and
    verification blocking sending is an admin setting."* Combined with the opt-in answer, this settles
@@ -3026,6 +3038,52 @@ day it ships.
    nine M12 phase PRs. Fix the trigger as Phase 8's first commit, or accept it deliberately?
    Recommendation: fix it. It is a two-line workflow change and the alternative is finding out about a
    Kotlin compile error during the cutover window.
+9. **Core's own `news.post` emitter — and the three other things a publish already fires.**
+   `config/coreTriggers.js` declares core's five triggers and says in as many words that **nothing here
+   emits yet**; Phase 6 migrated only the four `team.*` ones onto the engine. So `news.post` is a
+   declared payload contract with **no caller**, and on a real deployment the only in-app or email items
+   a rule can produce today come from Teams. Phase 7 found this and deliberately did not wire it, on the
+   grounds that a channel's own phase is not the place to give another phase's trigger an emitter.
+
+   **The call itself is one line. The care is entirely in what it must not disturb.**
+   `admin.controller.js`'s `announceIfNewlyPublished` already fans one publish four ways, and they are
+   different in kind — three of them are *not* the engagement engine's business:
+
+   | What fires on a publish | Whose | What kind of thing it is | The engine's? |
+   | --- | --- | --- | --- |
+   | `announceJobs.enqueueIfNeeded` → `announce_job_legs` | core, with legs registered by modules — `module-uo` owns `towncrier` | a one-shot **delivery to a channel of the deployment**, with retry and classification | **No** |
+   | `registries.dispatchPostHook('onSaved')` | modules, via `registerPostHook` (API 1.1.0) | idempotent **state mirroring** — it also runs on delete, and refreshes silently on an edit | **No** |
+   | `pushDispatch.publish('news.post', { ref })` | core | a **per-person notification**, to whoever subscribed | **Yes — this is the one that should become an emit** |
+   | *(missing)* `engagementEmit.emit('core', 'news.post', …)` | core | rules → email / in-app / push | **Yes** |
+
+   `registries.js` already states the first two apart and why they were not folded together ("a leg is a
+   one-shot DELIVERY with retry and classification; a post hook maintains idempotent STATE, has to run on
+   delete as well as save, and refreshes silently on an edit"). **Adding the engine makes a third
+   distinction of the same kind, not a replacement for either.** A module's town-crier leg and a module's
+   news gump must keep firing exactly as they do; what changes is only that the raw tickle stops being
+   the one person-facing sink and becomes one channel of a rule.
+
+   **What a module gets out of this, stated so nobody widens it by accident.** A module already has two
+   doors onto a news publish — the announce leg and the post hook — and it keeps both. What it does *not*
+   get is the ability to fire `news.post` itself: the id's owner is core, `ctx.events.emit` binds the
+   owner at the call and never reads it from the arguments, and §7.2's one namespace means an id has
+   exactly one owner across both facets. A module that wants a person-facing notification of its own
+   declares its own trigger through `registerEventTriggers`. That is the whole of "modules can use it".
+
+   **Three things to settle before anyone writes the line:**
+   - **Continuity, and it is the same shape as G22 and Phase 6's decision 3.** Today publishing news
+     tickles every `news.post` subscriber directly. If the emit *replaces* that call, push stops the
+     moment this lands and stays stopped until an operator enables a rule — silently, because `enabled`
+     defaults to `0`. Either core seeds a `news.post` rule (and then: enabled, against the standing
+     default, or disabled with a banner as the Team rules got?), or the raw tickle stays beside the emit
+     for one release and is removed once a rule is known to exist.
+   - **The transition signal must be reused, not re-derived.** `enqueueIfNeeded` returning a truthy job
+     id is the single "newly published news" test, and the push call already piggybacks on it
+     deliberately so an edit or a re-publish does not re-fire. The emit must gate on the same value; a
+     second reading of the transition is a second chance to disagree with the first.
+   - **Which phase owns it.** Recommendation: **Phase 11**, which already ships "the first real rule" and
+     is where a declared trigger first gets a caller. It is core work rather than `module-uo`'s, so that
+     phase's title understates it — say so there rather than inventing a phase for one call site.
 
 ### 7.2 One namespace, or two?