fix(web): address review findings on producer-declared context forms

- `catalogHistory` validated its durable read. `agent.session.events` is a
  JSONL/SQLite seed on resume or fork, and seed validation guarantees only a
  source object with a non-empty `kind`; a `skill-catalog` record with missing
  or wrongly shaped `entries` threw inside the step listener, failing every
  later turn of that session. It is now skipped as an unrecognizable record,
  the posture the replaced content digest had, with a regression test over six
  malformed shapes.
- The headless keyless smoke still filtered catalogs by the old plugin source,
  so the `built-bin-smoke` gate would not have found the catalog message.
- Entries record the published description unescaped. The pseudo-XML escaping
  belongs to the `<available_skills>` frame and is applied when rendering it,
  so a description containing `<` no longer reaches the card as `&lt;`.
  `escapeText` is injective, so republish semantics and the model-facing text
  are unchanged.
- Adjacent text blocks join with no separator, matching how provider adapters
  flatten them; the body no longer shows a line break the model never saw.
- Provenance fields are bounded like the text: an unknown producer may record
  an arbitrarily large value.
- Both readers are all-or-nothing, and the row's form marker reports what
  rendered rather than what was declared, so a partly unreadable record cannot
  present a confident but incomplete account.
- The catalog body consumes `update` as a replacement notice; the digest
  canonicalizes per entry as JSON, since every separator character is itself
  legal in a description.
- `core.md` documents the form axis with a `ContextForm` type-equiv block, and
  both projections assert the wiring they duplicate.

packages/client/ui-conversation/src/client/chat/ContextBody.module.css

@@ -65,7 +65,13 @@
   color: var(--dsw-alias-label-caption);
 }
 
-/* catalog: one row per published entry. */
+/* catalog: a replacement notice above one row per published entry. */
+.catalogNotice {
+  margin: 0 0 6px;
+  color: var(--dsw-alias-label-caption);
+}
+
+
 .entries {
   display: flex;
   flex-direction: column;

packages/client/ui-conversation/src/client/chat/ContextBody.tsx

@@ -5,7 +5,7 @@
 // even when this UI version has never seen its producer.
 
 import type { ReactNode } from 'react'
-import type { ContextMessageNode } from '@deepseek-ai/dsh-client-runtime/client'
+import type { ContextMessageNode, KnownContextForm } from '@deepseek-ai/dsh-client-runtime/client'
 import { JsonBlock } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { ChatViewSlotProps } from '../contract/slots.ts'
 import css from './ContextBody.module.css'
@@ -27,6 +27,9 @@ function asRecord(value: unknown): Record<string, unknown> | null {
  * Context is text in practice (every producer injects one text block), but the
  * block union is merge-extensible, so an unknown block keeps its own fallback
  * rather than vanishing.
+ *
+ * Blocks join with no separator, matching how provider adapters flatten them:
+ * inserting a line break here would show the reader a line the model never saw.
  */
 function partitionContent(content: ContextMessageNode['content']): { text: string; rest: unknown[] } {
   const texts: string[] = []
@@ -35,7 +38,7 @@ function partitionContent(content: ContextMessageNode['content']): { text: strin
     if (block.type === 'text') texts.push(block.text)
     else rest.push(block)
   }
-  return { text: texts.join('\n'), rest }
+  return { text: texts.join(''), rest }
 }
 
 /** The model-facing text, truncated to the display bound. */
@@ -45,11 +48,16 @@ function boundedText(text: string, t: Translate): string {
     : text
 }
 
-/** One source field rendered as a value row; nested shapes stay compact JSON. */
-function fieldValue(value: unknown): string {
-  if (typeof value === 'string') return value
-  if (typeof value === 'number' || typeof value === 'boolean') return String(value)
-  return JSON.stringify(value)
+/**
+ * One source field rendered as a value row; nested shapes stay compact JSON.
+ * Bounded on its own, because provenance is as unbounded as the text: an unknown
+ * producer may record an arbitrarily large string or array.
+ */
+function fieldValue(value: unknown, t: Translate): string {
+  const text = typeof value === 'string'
+    ? value
+    : typeof value === 'number' || typeof value === 'boolean' ? String(value) : JSON.stringify(value)
+  return boundedText(text, t)
 }
 
 /**
@@ -57,7 +65,7 @@ function fieldValue(value: unknown): string {
  * header already names the producer, and `form` because the presentation the
  * reader is looking at IS that value.
  */
-function SourceFields({ source }: { source: unknown }): ReactNode {
+function SourceFields({ source, t }: { source: unknown; t: Translate }): ReactNode {
   const record = asRecord(source)
   if (record === null) return null
   const rows = Object.entries(record).filter(([key]) => key !== 'kind' && key !== 'form')
@@ -67,7 +75,7 @@ function SourceFields({ source }: { source: unknown }): ReactNode {
       {rows.map(([key, value]) => (
         <div key={key} className={css.field}>
           <dt className={css.fieldKey}>{key}</dt>
-          <dd className={css.fieldValue}>{fieldValue(value)}</dd>
+          <dd className={css.fieldValue}>{fieldValue(value, t)}</dd>
         </div>
       ))}
     </dl>
@@ -98,7 +106,7 @@ export function OpaqueBody({ content, source, t }: {
           truncatedLabel={total => t('json.truncated', { total })}
         />
       ))}
-      <SourceFields source={source} />
+      <SourceFields source={source} t={t} />
     </>
   )
 }
@@ -110,26 +118,37 @@ interface InstructionChange {
   digest?: string
 }
 
-/** Instruction changes read off the source; empty when the shape is unusable. */
-function instructionChanges(source: unknown): InstructionChange[] {
+/**
+ * Instruction changes read off the source, or null when the record is not a
+ * usable instruction list.
+ *
+ * The read is all-or-nothing: silently dropping one unreadable entry would show
+ * a confident, incomplete file list for a log this version cannot fully read.
+ * Paths are deduplicated in first-seen order, matching how the header label is
+ * derived from the same array.
+ */
+function instructionChanges(source: unknown): InstructionChange[] | null {
   const record = asRecord(source)
   const list = record === null ? undefined : record['changes']
-  if (!Array.isArray(list)) return []
+  if (!Array.isArray(list)) return null
   const changes: InstructionChange[] = []
-  for (const entry of list) {
+  const seen = new Set<string>()
+  for (const entry of list as readonly unknown[]) {
     const change = asRecord(entry)
-    if (change === null) continue
+    if (change === null) return null
     const path = change['path']
-    if (typeof path !== 'string' || path === '') continue
+    if (typeof path !== 'string' || path === '') return null
     const action = change['action']
     const digest = change['digest']
+    if (seen.has(path)) continue
+    seen.add(path)
     changes.push({
       action: typeof action === 'string' ? action : '',
       path,
       ...typeof digest === 'string' ? { digest } : {},
     })
   }
-  return changes
+  return changes.length === 0 ? null : changes
 }
 
 /**
@@ -138,7 +157,8 @@ function instructionChanges(source: unknown): InstructionChange[] {
  * The text keeps its `<system-reminder>` framing verbatim — the framing is part
  * of what the model read, so hiding it would misreport the request.
  * @param props - Durable content, its source, and the locale seat.
- * @returns The instructions context body.
+ * @returns The instructions context body, or the opaque body when the change
+ * list is unreadable.
  */
 export function InstructionsBody({ content, source, t }: {
   content: ContextMessageNode['content']
@@ -146,22 +166,21 @@ export function InstructionsBody({ content, source, t }: {
   t: Translate
 }): ReactNode {
   const changes = instructionChanges(source)
+  if (changes === null) return <OpaqueBody content={content} source={source} t={t} />
   const baseline = asRecord(source)?.['baseline'] === true
   const { text, rest } = partitionContent(content)
   return (
     <>
-      {changes.length > 0 && (
-        <ul className={css.files} data-context-files>
-          {changes.map(change => (
-            <li key={change.path} className={css.file} title={change.digest}>
-              <span className={css.filePath}>{change.path}</span>
-              <span className={css.fileAction}>
-                {t(`message.context.instructions.${change.action === 'remove' ? 'removed' : baseline ? 'loaded' : 'updated'}`)}
-              </span>
-            </li>
-          ))}
-        </ul>
-      )}
+      <ul className={css.files} data-context-files>
+        {changes.map(change => (
+          <li key={change.path} className={css.file} title={change.digest}>
+            <span className={css.filePath}>{change.path}</span>
+            <span className={css.fileAction}>
+              {t(`message.context.instructions.${change.action === 'remove' ? 'removed' : baseline ? 'loaded' : 'updated'}`)}
+            </span>
+          </li>
+        ))}
+      </ul>
       {text !== '' && <pre className={css.text} data-context-text>{boundedText(text, t)}</pre>}
       {rest.map((block, index) => (
         <JsonBlock
@@ -181,21 +200,26 @@ interface CatalogEntry {
   description: string
 }
 
-/** Catalog entries read off the source; empty when the shape is unusable. */
-function catalogEntries(source: unknown): CatalogEntry[] {
+/**
+ * Catalog entries read off the source, or null when the record is not a usable
+ * catalog. All-or-nothing for the same reason as the instruction list: this body
+ * replaces the model-facing text, so a partial list would hide the only complete
+ * account of what the model read.
+ */
+function catalogEntries(source: unknown): CatalogEntry[] | null {
   const record = asRecord(source)
   const list = record === null ? undefined : record['entries']
-  if (!Array.isArray(list)) return []
+  if (!Array.isArray(list)) return null
   const entries: CatalogEntry[] = []
-  for (const item of list) {
+  for (const item of list as readonly unknown[]) {
     const entry = asRecord(item)
-    if (entry === null) continue
+    if (entry === null) return null
     const name = entry['name']
-    if (typeof name !== 'string' || name === '') continue
     const description = entry['description']
-    entries.push({ name, description: typeof description === 'string' ? description : '' })
+    if (typeof name !== 'string' || name === '' || typeof description !== 'string') return null
+    entries.push({ name, description })
   }
-  return entries
+  return entries.length === 0 ? null : entries
 }
 
 /**
@@ -205,7 +229,8 @@ function catalogEntries(source: unknown): CatalogEntry[] {
  * A catalog whose source carries no usable entries falls through to the opaque
  * body, so an older or hand-edited log still shows its text.
  * @param props - Durable content, its source, and the locale seat.
- * @returns The catalog context body.
+ * @returns The catalog context body, or the opaque body when the entry list is
+ * unreadable.
  */
 export function CatalogBody({ content, source, t }: {
   content: ContextMessageNode['content']
@@ -213,15 +238,55 @@ export function CatalogBody({ content, source, t }: {
   t: Translate
 }): ReactNode {
   const entries = catalogEntries(source)
-  if (entries.length === 0) return <OpaqueBody content={content} source={source} t={t} />
+  if (entries === null) return <OpaqueBody content={content} source={source} t={t} />
+  const update = asRecord(source)?.['update'] === true
   return (
-    <ul className={css.entries} data-context-entries>
-      {entries.map(entry => (
-        <li key={entry.name} className={css.entry}>
-          <code className={css.entryName}>{entry.name}</code>
-          <span className={css.entryDescription}>{entry.description}</span>
-        </li>
-      ))}
-    </ul>
+    <>
+      {update && <p className={css.catalogNotice} data-context-catalog-update>{t('message.context.catalog.replaced')}</p>}
+      <ul className={css.entries} data-context-entries>
+        {entries.map((entry, index) => (
+          // Index key: a hand-edited or foreign log may repeat a name, and a
+          // duplicate React key would drop a row the model did see.
+          <li key={index} className={css.entry}>
+            <code className={css.entryName}>{entry.name}</code>
+            <span className={css.entryDescription}>{entry.description}</span>
+          </li>
+        ))}
+      </ul>
+    </>
   )
 }
+
+/**
+ * Choose the body for one context node.
+ *
+ * Returns the form the body actually rendered as, which is not always the
+ * declared one: a declared form whose fields are unreadable falls back to
+ * opaque, and the caller labels the row with what it really shows.
+ * @param form - the producer-declared form projected onto the node.
+ * @param props - durable content, its source, and the locale seat.
+ * @returns the rendered form (null for opaque) and its body.
+ */
+export function contextBody(
+  form: ContextMessageNode['form'],
+  props: { content: ContextMessageNode['content']; source: unknown; t: Translate },
+): { rendered: KnownContextForm | null; body: ReactNode } {
+  switch (form) {
+    case 'instructions':
+      return instructionChanges(props.source) === null
+        ? { rendered: null, body: <OpaqueBody {...props} /> }
+        : { rendered: 'instructions', body: <InstructionsBody {...props} /> }
+    case 'catalog':
+      return catalogEntries(props.source) === null
+        ? { rendered: null, body: <OpaqueBody {...props} /> }
+        : { rendered: 'catalog', body: <CatalogBody {...props} /> }
+    case null:
+      return { rendered: null, body: <OpaqueBody {...props} /> }
+    /* v8 ignore next 4 -- closed-union backstop; the compiler rejects a new
+    KnownContextForm here rather than letting it degrade to opaque silently. */
+    default: {
+      const unreachable: never = form
+      throw new Error(`unreachable context form: ${String(unreachable)}`)
+    }
+  }
+}

packages/client/ui-conversation/src/client/chat/ContextInjectionRow.tsx

@@ -3,7 +3,7 @@ import type { ContextMessageNode } from '@deepseek-ai/dsh-client-runtime/client'
 import type { ChatViewSlotProps } from '../contract/slots.ts'
 import { IconBrowseOutline16 } from '@deepseek-ai/dsh-client-ui-primitives'
 import { DisclosureRow } from './DisclosureRow.tsx'
-import { CatalogBody, InstructionsBody, OpaqueBody } from './ContextBody.tsx'
+import { contextBody } from './ContextBody.tsx'
 import css from './ContextInjectionRow.module.css'
 
 /** Props for the logged non-user message presentation. */
@@ -31,6 +31,9 @@ export interface ContextInjectionRowProps {
  */
 export function ContextInjectionRow({ content, source, provenance, form, t }: ContextInjectionRowProps) {
   const [open, setOpen] = useState(false)
+  // Resolved rather than declared: a form whose fields are unreadable renders
+  // the opaque body, and the marker must say what the row actually shows.
+  const { rendered, body } = contextBody(form, { content, source, t })
 
   return (
     <DisclosureRow
@@ -53,12 +56,8 @@ export function ContextInjectionRow({ content, source, provenance, form, t }: Co
       expandOnRowClick
       onToggle={() => { setOpen(value => !value) }}
     >
-      <div className={css.body} data-context-injection-body data-context-form={form ?? undefined}>
-        {form === 'instructions'
-          ? <InstructionsBody content={content} source={source} t={t} />
-          : form === 'catalog'
-            ? <CatalogBody content={content} source={source} t={t} />
-            : <OpaqueBody content={content} source={source} t={t} />}
+      <div className={css.body} data-context-injection-body data-context-form={rendered ?? undefined}>
+        {body}
       </div>
     </DisclosureRow>
   )

packages/client/ui-conversation/src/client/locales.ts

@@ -58,6 +58,7 @@ export const zh = {
   'message.context.instructions.loaded': '已载入',
   'message.context.instructions.updated': '已更新',
   'message.context.instructions.removed': '已移除',
+  'message.context.catalog.replaced': '替换目录',
   'message.steering': '插话',
   'message.compaction': '上下文已压缩',
   'message.compaction.expand': '点击查看压缩摘要',
@@ -176,6 +177,7 @@ export const en = {
   'message.context.instructions.loaded': 'loaded',
   'message.context.instructions.updated': 'updated',
   'message.context.instructions.removed': 'removed',
+  'message.context.catalog.replaced': 'Replacement catalog',
   'message.steering': 'Interjection',
   'message.compaction': 'Context compacted',
   'message.compaction.expand': 'View compaction summary',