fix: put the recall chip in the header utilities, not the cell the sidebar's expand button owns

The chip registered into `conversation.session.header.corner`, which is a
SINGLE cell the product already occupies: the client catalog lists its
occupants as `client-ui-sidebar-right ExpandButton` and its replaceRisk as
`shadows-shipped-ui`. Two registrations at priority 0 in a single cell are a
hard error inside the slot registry, and the error lands in the OTHER
plugin's `slots.inject()` callback: the renderer's `changed` handler catches
it, calls `stop()` on that inject controller — killing that contribution for
the rest of the fiber's life — and rethrows it from a microtask, which is the
uncaught `single slot ... already has a registration at priority 0 (registered
by dsh-recall)` in the console. So the chip was not merely racing the shipped
right-sidebar expand control; it was taking it down.

It now registers into `conversation.session.header.utilities`, a list cell
(`replaceRisk: none`, right-aligned, same Session scope and therefore the same
`useProjection` prop) as `{ id: 'dsh-recall', order: 20 }`, so it stays at the
right-hand end without competing for a seat.

The suite could not have caught this: the slot stub accepts any registration
and knows nothing about cardinality, keys or collisions. It now asserts the
chip carries a list id and that this plugin registers nothing into the corner.

README.md

@@ -146,18 +146,20 @@ Parameters: `query`, `action`, `limit`, `path` (restrict to a subdirectory),
 
 Two surfaces, both reading a host projection rather than polling:
 
-- a **chip in the session header** — `Recall 3 · 40× · 457 KB kept out`. No price
+- a **chip in the session header's utilities** — `Recall 3 · 40× · 457 KB kept
-  on it, deliberately: at the measured rate a whole conversation's avoided
+  out`. No price on it, deliberately: at the measured rate a whole conversation's
-  context is a fraction of a penny, and a chip advertising that reads as the tool
+  avoided context is a fraction of a penny, and a chip advertising that reads as
-  being useless rather than as the arithmetic being honest. The tooltip carries
+  the tool being useless rather than as the arithmetic being honest. The tooltip
-  the full comparison.
+  carries the full comparison.
 - a **right-sidebar Recall tab** — the same figures with room for what they are
   not: *"An estimate, and an upper bound: it assumes a whole file would have been
   read each time. Token counts are bytes ÷ 4."*
 
 Both render nothing when there is nothing to say — a conversation that never used
-recall costs no layout at all, which matters for the header corner because the
+recall costs no layout at all. The chip is an entry in the header's `utilities`
-framework lays it out only while its occupant renders something.
+list, carrying its own id. The far-right corner is deliberately left alone: it is
+a single cell that the product's own right-sidebar expand control occupies, so a
+registration there shadows shipped UI rather than sitting beside it.
 
 The data path is `presentationMeta` → the `tool/result` event's `meta` → a
 projection unit (`recallUsage`) with a wire view the browser reads through

client/client.js

@@ -4,7 +4,7 @@
  * Three contributions, each into a seat the Harness 0.1.7 composition declares:
  *
  *   1. the plugin's configuration page, in the **Plugins** panel;
- *   2. a one-line usage chip in a conversation's header corner;
+ *   2. a one-line usage chip in a conversation's header utilities;
  *   3. a right-sidebar tab with the same figures and room for their caveats.
  *
  * **Where plugin settings live now.** 0.1.5 drew plugin configuration as cards
@@ -620,8 +620,8 @@ window.__ModuleLoader__.load({
 
     function RecallChip(props) {
       const usage = useUsage(props)
-      // The corner is laid out only while its occupant renders something, so a
+      // The utilities list draws nothing for an entry that renders nothing, so
-      // conversation that never called the tool costs no layout at all.
+      // a conversation that never called the tool costs no layout at all.
       if (usage === undefined || !usage.searches) return null
       return h(
         'span',
@@ -735,10 +735,28 @@ window.__ModuleLoader__.load({
         )
       })
 
-      // The chip: the header's far-right corner, which the framework lays out
+      // The chip: a right-aligned session utility, next to the header's
-      // only while its occupant renders something.
+      // far-right corner.
-      ctx.slots.inject('conversation.session.header.corner', () =>
+      //
-        ctx.slots.register({ name: 'conversation.session.header.corner' }, (props) => h(RecallChip, props)),
+      // It is in the `utilities` LIST, not the corner, and that is not a
+      // cosmetic choice. The corner is a `single` cell whose occupant the
+      // product already declares — `client-ui-sidebar-right ExpandButton`, the
+      // right sidebar's expand control — and the client catalog reports it as
+      // `replaceRisk: "shadows-shipped-ui"`. A second registration at the same
+      // priority is a hard error inside the slot registry, thrown while the
+      // other plugin's `slots.inject()` callback runs: the renderer catches it,
+      // STOPS that inject controller for the rest of the fiber's life, and
+      // rethrows it uncaught. So squatting there did not merely race — it took
+      // the shipped expand control down and logged an uncaught error. A list
+      // entry carrying its own id cannot collide with anyone, and the framework
+      // draws nothing for an entry that renders nothing.
+      ctx.slots.inject('conversation.session.header.utilities', () =>
+        ctx.slots.register(
+          // `order` ascends left to right, so a high value keeps the chip at
+          // the right-hand end of the utilities, where it was before.
+          { name: 'conversation.session.header.utilities', id: 'dsh-recall', order: 20 },
+          (props) => h(RecallChip, props),
+        ),
       )
 
       // The right-sidebar tab is registered in two stages, and the second is

test/client.test.js

@@ -405,17 +405,32 @@ test('the chip and the sidebar tab survive a deployment with no settings provide
   // profile without a settings provider loses the page and keeps the rest.
   const { registered, tabTypes } = mount({ withConfigForms: false })
   assert.deepEqual(registered.map((item) => item.meta.name).sort(), [
-    'conversation.session.header.corner',
+    'conversation.session.header.utilities',
     'sidebar.right.pane.tab',
   ])
   assert.equal(tabTypes.length, 1, 'the tab type is independent of settings')
 })
 
-test('the header chip is a single-seat contribution with no key', () => {
+test('the header chip is an additive list entry carrying its own id', () => {
+  // The header's far-right corner is a SINGLE cell, and the product already
+  // occupies it with its right-sidebar expand control — the client catalog
+  // reports that key as `replaceRisk: "shadows-shipped-ui"`. A second
+  // registration at the same priority is a hard error inside the registry,
+  // thrown while the OTHER plugin's `slots.inject()` callback runs: the
+  // renderer catches it, stops that controller for the rest of the fiber's
+  // life, and rethrows it uncaught. So the chip belongs in a list cell, where
+  // a unique id makes it additive.
   const { registered } = mount()
-  const chip = registered.find((item) => item.meta.name === 'conversation.session.header.corner')
+  const chip = registered.find((item) => item.meta.name === 'conversation.session.header.utilities')
   assert.ok(chip !== undefined)
-  assert.equal(chip.meta.key, undefined, 'the corner is a single seat, so it takes no key')
+  assert.equal(chip.meta.id, 'dsh-recall', 'a list cell is addressed by its id')
+  assert.equal(typeof chip.meta.order, 'number', 'the order places the cell within the list')
+  assert.equal(chip.meta.key, undefined, 'a list cell takes an id, not a key')
+  assert.deepEqual(
+    registered.filter((item) => item.meta.name === 'conversation.session.header.corner'),
+    [],
+    'the corner is a single cell the product owns; a registration there shadows shipped UI',
+  )
 })
 
 test('the sidebar tab registers a type AND a body under the same id', () => {
@@ -440,7 +455,7 @@ test('the sidebar tab registers a type AND a body under the same id', () => {
 test('the browser half contributes three seats, none of them the retired 0.1.5 one', () => {
   const { registered } = mount()
   assert.deepEqual(registered.map((item) => item.meta.name).sort(), [
-    'conversation.session.header.corner',
+    'conversation.session.header.utilities',
     'plugins.bundle.config',
     'sidebar.right.pane.tab',
   ])
@@ -590,17 +605,17 @@ function usageView(overrides = {}) {
 
 test('the header chip renders nothing when the conversation never used it', () => {
   const { renderSlot } = mount()
-  // The corner is laid out only while its occupant renders something, so this
+  // The utilities list draws nothing for an entry that renders nothing, so
-  // is the state that must cost no space at all.
+  // this is the state that must cost no space at all.
-  assert.equal(renderSlot('conversation.session.header.corner', { useProjection: () => undefined }), null)
+  assert.equal(renderSlot('conversation.session.header.utilities', { useProjection: () => undefined }), null)
-  assert.equal(renderSlot('conversation.session.header.corner', { useProjection: () => usageView({ searches: 0, excerpts: 0 }) }), null)
+  assert.equal(renderSlot('conversation.session.header.utilities', { useProjection: () => usageView({ searches: 0, excerpts: 0 }) }), null)
   // And a host without the projection service at all.
-  assert.equal(renderSlot('conversation.session.header.corner', {}), null)
+  assert.equal(renderSlot('conversation.session.header.utilities', {}), null)
 })
 
 test('the header chip leads with what was kept out, not what it cost', () => {
   const { renderSlot } = mount()
-  const chip = renderSlot('conversation.session.header.corner', { useProjection: () => usageView() })
+  const chip = renderSlot('conversation.session.header.utilities', { useProjection: () => usageView() })
   assert.ok(chip !== null)
   const text = String(chip.props.children)
   assert.match(text, /Recall 3/)
@@ -613,7 +628,7 @@ test('the header chip leads with what was kept out, not what it cost', () => {
 
 test('the chip tooltip carries the figures the chip has no room for', () => {
   const { renderSlot } = mount()
-  const chip = renderSlot('conversation.session.header.corner', { useProjection: () => usageView({ rereadTokens: 500_000 }) })
+  const chip = renderSlot('conversation.session.header.utilities', { useProjection: () => usageView({ rereadTokens: 500_000 }) })
   const detail = chip.props.title
   assert.match(detail, /3 searches/)
   assert.match(detail, /9 excerpts from 5 files/)