fix(web): align the context separator with ToolRow and name the caption

Review follow-ups on the context provenance row:

- the producer name now follows ToolRow's aria-hidden separator dot instead
  of a literal middot inside the text, so the two disclosure rows expose one
  accessible-name shape;
- the English steering caption becomes the noun `Interjection`, parallel to
  the Chinese 插话 and to the label this bubble carried before;
- the history fold gets its own provenance assertion, so the mapping it
  declares separately from TranscriptAdapter is pinned on both sides;
- the superseded-in-part bullet on the no-interjection-chrome note now
  enumerates the third Decision bullet too, whose no-badge and no-IconActions
  clauses had both lapsed.

apps/web/tests/snapshots/queue-actions/collapsed.expected.md

@@ -10,10 +10,10 @@
 - button "Branch into a new conversation" [disabled]:
   - img
 - text: Available only on the last message of a completed turn
-- button "Context injection · @deepseek-ai/dsh-system-prompt":
+- button "Context injection @deepseek-ai/dsh-system-prompt":
   - img
   - img
-  - text: Context injection · @deepseek-ai/dsh-system-prompt
+  - text: Context injection @deepseek-ai/dsh-system-prompt
 - paragraph: partial
 - status: Deep diving...
 - button "2 queued messages"

apps/web/tests/snapshots/queue-actions/editing.expected.md

@@ -10,10 +10,10 @@
 - button "Branch into a new conversation" [disabled]:
   - img
 - text: Available only on the last message of a completed turn
-- button "Context injection · @deepseek-ai/dsh-system-prompt":
+- button "Context injection @deepseek-ai/dsh-system-prompt":
   - img
   - img
-  - text: Context injection · @deepseek-ai/dsh-system-prompt
+  - text: Context injection @deepseek-ai/dsh-system-prompt
 - paragraph: partial
 - status: Deep diving...
 - button "2 queued messages" [disabled] [expanded]

apps/web/tests/snapshots/queue-actions/layout.expected.md

@@ -8,18 +8,18 @@
   - img
   - img
   - text: "goal Goal created Status: active Objective: Keep the composer context panels aligned Rounds: 0/256 Activation: armed Commands: /goal edit <objective>, /goal pause, /goal clear"
-- button "Context injection · goal":
+- button "Context injection goal":
   - img
   - img
-  - text: Context injection · goal
-- button "Context injection · goal":
+  - text: Context injection goal
+- button "Context injection goal":
   - img
   - img
-  - text: Context injection · goal
-- button "Context injection · @deepseek-ai/dsh-system-prompt":
+  - text: Context injection goal
+- button "Context injection @deepseek-ai/dsh-system-prompt":
   - img
   - img
-  - text: Context injection · @deepseek-ai/dsh-system-prompt
+  - text: Context injection @deepseek-ai/dsh-system-prompt
 - paragraph: partial
 - status: Deep diving...
 - region "To-dos":

apps/web/tests/snapshots/queue-actions/preserved.expected.md

@@ -10,10 +10,10 @@
 - button "Branch into a new conversation" [disabled]:
   - img
 - text: Available only on the last message of a completed turn
-- button "Context injection · @deepseek-ai/dsh-system-prompt":
+- button "Context injection @deepseek-ai/dsh-system-prompt":
   - img
   - img
-  - text: Context injection · @deepseek-ai/dsh-system-prompt
+  - text: Context injection @deepseek-ai/dsh-system-prompt
 - paragraph: partial
 - text: Stopped
 - button "Copy":

apps/web/tests/snapshots/queue-actions/ui.expected.md

@@ -10,10 +10,10 @@
 - button "Branch into a new conversation" [disabled]:
   - img
 - text: Available only on the last message of a completed turn
-- button "Context injection · @deepseek-ai/dsh-system-prompt":
+- button "Context injection @deepseek-ai/dsh-system-prompt":
   - img
   - img
-  - text: Context injection · @deepseek-ai/dsh-system-prompt
+  - text: Context injection @deepseek-ai/dsh-system-prompt
 - paragraph: partial
 - status: Deep diving...
 - list: