feat(acp): enable automatic compaction

examples/acp-agent/composition.md

@@ -27,6 +27,8 @@ flowchart LR
   bundle_agent_core --> spine_sessions["ctx.sessions"]
   bundle_agent_core --> spine_tools["ctx.tools + tool-bash"]
   bundle_agent_core --> spine_loop["ctx.agents + ctx.agentLoop"]
+  plugin_acp_compact_basic["compact-basic<br/>@deepseek-ai/dsh-compact-basic"]
+  cfg --> plugin_acp_compact_basic
   plugin_acp_subagent["subagent<br/>@deepseek-ai/dsh-subagent"]
   cfg --> plugin_acp_subagent
   plugin_acp_subagent_spawn["subagent-spawn<br/>@deepseek-ai/dsh-subagent-spawn"]
@@ -59,6 +61,7 @@ flowchart LR
 | `approval` | `@deepseek-ai/dsh-user-approval` |
 | `permission` | `@deepseek-ai/dsh-permission` |
 | `acp-agent` | `@deepseek-ai/dsh-acp-agent` |
+| `compact-basic` | `@deepseek-ai/dsh-compact-basic` |
 | `subagent` | `@deepseek-ai/dsh-subagent` |
 | `subagent-spawn` | `@deepseek-ai/dsh-subagent-spawn` |
 | `subagent-fork` | `@deepseek-ai/dsh-subagent-fork` |

examples/acp-agent/cordis.yml

@@ -48,6 +48,18 @@
 
       Verify your work by running the code or tests. Keep answers brief and factual.
 
+# Summarize an older range when derived history approaches the context window.
+# This leaf consumes `ctx.llm` and the app's `agent/pre-step` seam.
+- id: compact-basic
+  name: '@deepseek-ai/dsh-compact-basic'
+  config:
+    contextWindow: 128000
+    thresholdRatio: 0.8
+    retainTokens: 20480
+    summarizationModel: ''
+    maxTokens: 8192
+    compactionRetries: 1
+
 # Expose fresh-child `spawn` and completed-prefix `fork` through separate tool
 # names so multi-child scenarios exercise both transports. These leaves follow
 # the app because it provides `ctx.agents` and `ctx.tools`.