feat(desktop): attribute a sub-agent's work to it, and show what it did (R5)

desktop/electron/resources/agent_families.generated.json

@@ -89,9 +89,11 @@
             "payload": {
               "description": "$.description",
               "last_tool_name": "$.last_tool_name",
+              "subagent_type": "$.subagent_type",
               "subtype": "$.subtype",
               "task_id": "$.task_id",
-              "text": "$.description"
+              "text": "$.description",
+              "tool_use_id": "$.tool_use_id"
             }
           }
         },
@@ -140,6 +142,9 @@
                 "producer": "agent",
                 "payload": {
                   "message_id": "$$.message.id",
+                  "parent_tool_use_id": "$$.parent_tool_use_id",
+                  "subagent": "present($$.parent_tool_use_id)",
+                  "subagent_type": "$$.subagent_type",
                   "text": "$.text"
                 }
               }
@@ -154,7 +159,10 @@
                 "payload": {
                   "id": "$.id",
                   "input": "$.input",
-                  "name": "$.name"
+                  "name": "$.name",
+                  "parent_tool_use_id": "$$.parent_tool_use_id",
+                  "subagent": "present($$.parent_tool_use_id)",
+                  "subagent_type": "$$.subagent_type"
                 }
               }
             },
@@ -168,7 +176,10 @@
                 "payload": {
                   "marker_only": "absent($.thinking)",
                   "message_id": "$$.message.id",
+                  "parent_tool_use_id": "$$.parent_tool_use_id",
                   "signature_present": "present($.signature)",
+                  "subagent": "present($$.parent_tool_use_id)",
+                  "subagent_type": "$$.subagent_type",
                   "text": "nonempty($.thinking) || \"Thinking…\""
                 }
               }
@@ -190,7 +201,10 @@
               "message_id": "$.message.id",
               "model": "$.message.model",
               "output_tokens": "$.message.usage.output_tokens",
-              "service_tier": "$.message.usage.service_tier"
+              "parent_tool_use_id": "$.parent_tool_use_id",
+              "service_tier": "$.message.usage.service_tier",
+              "subagent": "present($.parent_tool_use_id)",
+              "subagent_type": "$.subagent_type"
             }
           }
         },
@@ -213,6 +227,9 @@
                 "payload": {
                   "content": "$.content",
                   "is_error": "$.is_error",
+                  "parent_tool_use_id": "$$.parent_tool_use_id",
+                  "subagent": "present($$.parent_tool_use_id)",
+                  "subagent_type": "$$.subagent_type",
                   "tool_use_id": "$.tool_use_id"
                 }
               }

desktop/src/i18n/index.ts

@@ -451,6 +451,10 @@ const en: Dict = {
   'tx.dock.todos': 'Todos ({done}/{total})',
   'tx.dock.close': 'Close panel',
   'tx.dock.noTodos': 'No todos in the latest plan.',
+  // R5 — one sub-agent's own activity.
+  'tx.dock.back': 'Back to the list',
+  'tx.dock.subQuiet': 'This sub-agent has not done anything yet.',
+  'tx.dock.subUnreported': 'This engine does not report which events are a sub-agent’s, so its work cannot be separated from the main agent’s here. The request above is what it was asked to do.',
   'tx.now': 'now',
   'composer.attach': 'Attach file or image',
   'composer.slashMenu': 'Slash commands',
@@ -2894,6 +2898,10 @@ const zh: Dict = {
   'tx.dock.todos': '待办 ({done}/{total})',
   'tx.dock.close': '关闭面板',
   'tx.dock.noTodos': '最新的计划中没有待办。',
+  // R5 — 单个子代理的活动。
+  'tx.dock.back': '返回列表',
+  'tx.dock.subQuiet': '该子代理尚未有任何动作。',
+  'tx.dock.subUnreported': '该引擎不会标明哪些事件来自子代理，因此这里无法把它的工作与主代理分开。上方显示的是它被要求完成的任务。',
   'tx.now': '刚刚',
   'composer.attach': '附加文件或图片',
   'composer.slashMenu': '斜杠命令',

desktop/src/styles/partials/05-transcript-boards.css

@@ -703,6 +703,79 @@
   padding: var(--spacing-s4) 0;
   font-size: var(--font-size-body-small);
 }
+
+/* R5 — a sub-agent row opens that agent's own activity. The button carries
+   the row's layout so the drill-down affordance doesn't reflow the list; only
+   the chevron is new. Shell rows keep the plain <li> and are unaffected. */
+.sd-row-open {
+  display: flex;
+  align-items: center;
+  gap: var(--spacing-s6);
+  flex: 1;
+  min-width: 0;
+  padding: 0;
+  border: 0;
+  border-radius: var(--radius-sm);
+  background: transparent;
+  color: inherit;
+  font: inherit;
+  text-align: left;
+  cursor: pointer;
+}
+.sd-row-open:hover {
+  background: var(--surface-hover);
+}
+.sd-row-chev {
+  margin-left: auto;
+  opacity: 0.5;
+}
+.sd-sub {
+  display: flex;
+  flex-direction: column;
+  gap: var(--spacing-s4);
+  min-width: 0;
+}
+.sd-sub-type {
+  display: inline-flex;
+  align-items: center;
+  gap: var(--spacing-s4);
+  color: var(--text-muted);
+  font-size: var(--font-size-caption);
+}
+/* The prompt is the one thing every engine can show, so it gets room to be
+   read — wrapped and selectable, not clamped to a row. */
+.sd-sub-prompt {
+  max-height: 7em;
+  overflow-y: auto;
+  padding: var(--spacing-s4) var(--spacing-s8);
+  border-left: 2px solid var(--border);
+  color: var(--text);
+  font-size: var(--font-size-body-small);
+  white-space: pre-wrap;
+  overflow-wrap: anywhere;
+}
+.sd-sub-now {
+  font-size: var(--font-size-caption);
+  font-style: italic;
+}
+.sd-sub-line {
+  gap: var(--spacing-s4);
+}
+.sd-sub-detail {
+  min-width: 0;
+  overflow: hidden;
+  color: var(--text-muted);
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+/* Prose the sub-agent produced reads as prose, not as a tool row. */
+.sd-sub-line.k-text .sd-sub-detail {
+  color: var(--text);
+}
+.sd-sub-line.k-thought .sd-sub-detail {
+  font-style: italic;
+  opacity: 0.8;
+}
 .sd-row-name {
   flex: 0 0 auto;
   font-weight: 600;

desktop/src/surfaces/AgentTranscript.tsx

@@ -21,7 +21,7 @@ import { agentIsBusy, errorLabel, eventIsError, FEED_LENSES, isHiddenInFeed, mat
 import { collapseStreamingPartials } from '../ui/streamingPartials';
 import { groupToolCalls, toolCallUpdateParentId, type FeedRow } from '../ui/toolGroups';
 import { ToolGroupCard } from '../ui/ToolGroupCard';
-import { deriveStateDock } from '../ui/stateDock';
+import { deriveStateDock, subagentDetail, type DockCall } from '../ui/stateDock';
 // NB explicit .tsx: the pure module `stateDock.ts` differs from this file
 // name only in casing, so on macOS's case-insensitive filesystem a bare
 // '../ui/StateDock' import resolves to stateDock.ts (TS1149). The extension
@@ -396,6 +396,13 @@ export function AgentTranscript({ agentId, sessionId }: { agentId: string; sessi
     () => deriveStateDock(feed, { nameById, resultById, updateById }),
     [feed, nameById, resultById, updateById],
   );
+  // R5 — one sub-agent's own activity, resolved on demand. A callback rather
+  // than a precomputed map because only the row the director opened needs the
+  // scan, and the dock re-derives on every event.
+  const subagentDetailFor = useCallback(
+    (call: DockCall) => subagentDetail(feed, call, { nameById, resultById, updateById }),
+    [feed, nameById, resultById, updateById],
+  );
   // P1 tool-group collapse state (kimi-web parity — plan §7 decision 3):
   // groups are EXPANDED by default and never auto-collapse; the header click
   // is the only toggle, opt-in per group instance. Keyed by the group's
@@ -1314,7 +1321,7 @@ export function AgentTranscript({ agentId, sessionId }: { agentId: string; sessi
           )}
           {/* P2 state dock — live mode only, outside the virtual list,
               directly above the composer. */}
-          <StateDock model={stateDock} />
+          <StateDock model={stateDock} subagentDetailFor={subagentDetailFor} />
           {/* R2 — the ring sits in the composer's own row, not the header
               strip, because its question ("is there room for this prompt?")
               is asked while typing. The strip keeps the same numbers as text