feat(web): a prose mention of a produced file opens it

The chatFileMentions service (provided by ui-deliverables beside its
turn-tail entry, reached via ctx.get) resolves inline-code tokens in the
closing message against the turn's produced locations: exact path or
unique basename links, ambiguity and unknowns stay inert. MarkdownText
gains the optional fileMentions seam — settled renders only, never
inside anchors.

packages/client/ui-deliverables/src/client/ProducedFiles.tsx

@@ -6,18 +6,13 @@
 
 import type { PropsLocale } from '@deepseek-ai/dsh-client-ui-slots'
 import type { TurnTailOwnerProps } from '@deepseek-ai/dsh-client-ui-conversation/client'
+import { basename } from './turn-deliverables.ts'
 import type { NS } from './locales.ts'
 import css from './ProducedFiles.module.css'
 
 /** Files past this stay counted but unlisted: a refactor turn must not bury the answer. */
 const SHOWN = 6
 
-/** Trailing path segment, the part that identifies the file at a glance. */
-function basename(path: string): string {
-  const at = Math.max(path.lastIndexOf('/'), path.lastIndexOf('\\'))
-  return at === -1 ? path : path.slice(at + 1)
-}
-
 /** Matched paths plus the opener and locale seats needed to present them. */
 export type ProducedFilesProps = Pick<TurnTailOwnerProps, 'openFile'> & {
   matched: readonly string[]

packages/client/ui-deliverables/src/client/index.ts

@@ -1,16 +1,18 @@
 /**
  * Deliverables plugin, browser half: registers the produced-files row into
- * the chat view's turn-tail hole. All policy lives here — the derivation
- * from the mutation tools' `locations`, the chip cap, and the copy — so
- * composing this plugin out of cordis.yml removes the surface entirely; the
- * owning view renders an empty hole at zero cost.
+ * the chat view's turn-tail chain, and provides the `chatFileMentions`
+ * service that links inline-code mentions of produced files in the closing
+ * prose. All policy lives here — the derivation from the mutation tools'
+ * `locations`, the mention matching, the chip cap, and the copy — so
+ * composing this plugin out of cordis.yml removes both surfaces entirely;
+ * the owning view renders an empty chain and inert prose at zero cost.
  */
 import type { ClientContext } from '@deepseek-ai/dsh-client-runtime/client'
-import type {} from '@deepseek-ai/dsh-client-ui-conversation/client'
+import type { ChatFileMentions } from '@deepseek-ai/dsh-client-ui-conversation/client'
 import type {} from '@deepseek-ai/dsh-client-locale/client'
 import { ProducedFiles } from './ProducedFiles.tsx'
 import { en, NS, zh, type DeliverablesKey } from './locales.ts'
-import { selectProducedFiles } from './turn-deliverables.ts'
+import { producedFileMentions, producedForClosing, selectProducedFiles } from './turn-deliverables.ts'
 
 declare module '@deepseek-ai/dsh-client-ui-slots' {
   interface LocaleNamespaceMap {
@@ -39,4 +41,15 @@ export function apply(ctx: ClientContext): void {
       locale: NS,
     }, ProducedFiles),
   )
+  // The prose side of the same vocabulary: the chat view reaches this face
+  // via ctx.get, so its absence — this plugin composed out — is the off state.
+  const t = ctx.locale.bind(NS)
+  const mentions: ChatFileMentions = {
+    forClosing(owner) {
+      const paths = producedForClosing(owner.nodes, owner.seq)
+      if (paths.length === 0) return undefined
+      return producedFileMentions(paths, owner.openFile, path => t('produced.open', { name: path }))
+    },
+  }
+  ctx.provide('chatFileMentions', mentions)
 }

packages/client/ui-deliverables/src/client/turn-deliverables.ts

@@ -4,6 +4,7 @@
  * own follow-along `locations`, never the closing prose.
  */
 import type { ConversationNode, ToolResultNode } from '@deepseek-ai/dsh-client-runtime/client'
+import type { MarkdownFileMentions } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { TurnTailOwnerProps } from '@deepseek-ai/dsh-client-ui-conversation/client'
 
 /**
@@ -88,3 +89,45 @@ export function selectProducedFiles(owner: TurnTailOwnerProps): readonly string[
   const paths = producedForClosing(nodes, seq)
   return paths.length === 0 ? null : paths
 }
+
+/**
+ * Trailing path segment, the part that identifies the file at a glance.
+ * @param path - Slash- or backslash-separated path.
+ * @returns The final segment, or the whole string when separator-free.
+ */
+export function basename(path: string): string {
+  const at = Math.max(path.lastIndexOf('/'), path.lastIndexOf('\\'))
+  return at === -1 ? path : path.slice(at + 1)
+}
+
+/**
+ * File-mention vocabulary over one turn's produced paths, for the closing
+ * message's prose: an inline-code token opens the file it names. A token
+ * resolves by exact path, or by being exactly the basename of exactly one
+ * produced path — a basename two paths share stays inert rather than
+ * guessing, so a mention link can never open the wrong file or 404.
+ * @param paths - The turn's produced paths (tool order, already deduped).
+ * @param openFile - The chat view's file opener.
+ * @param label - Localizes the accessible open-label for a resolved path.
+ * @returns The resolver MarkdownText consumes; the full path rides `title`,
+ * the same disambiguator the row's chips carry.
+ */
+export function producedFileMentions(
+  paths: readonly string[],
+  openFile: (path: string) => void,
+  label: (path: string) => string,
+): MarkdownFileMentions {
+  return {
+    resolve(value) {
+      const path = paths.includes(value) ? value : onlyPathWithBasename(paths, value)
+      if (path === undefined) return undefined
+      return { open: () => { openFile(path) }, label: label(path), title: path }
+    },
+  }
+}
+
+/** The single produced path whose basename is exactly `value`, else undefined. */
+function onlyPathWithBasename(paths: readonly string[], value: string): string | undefined {
+  const matches = paths.filter(path => basename(path) === value)
+  return matches.length === 1 ? matches[0] : undefined
+}