feat(dynamic-trim): rename trim-tool-result, add self-compact, drop list-tool-results

Align the openclaw side of the dynamic-* tool family with the new
Plexum design (decision #31, 2026-06-04 revision):

- trim-tool-result → dynamic-trim (same on-wire schema; same semantics)
- Drop list-tool-results entirely. Agents find the opaque tool_call_id
  by reading their own prior assistant message's toolCall block id
  instead of querying a separate "directory" tool. This removes a
  workflow-step prerequisite and matches how Anthropic-shaped APIs
  surface tool_use ids to the model anyway.
- On agent_end drain, ALSO self-compact the dynamic-trim's own
  tool_use.input: rewrite to {tool_call_id, _self_compacted: true}.
  Without this the bulky `replacement` text sits duplicated — once in
  the rewritten target tool_result, once in dynamic-trim's call input.
  Picks up the selfCallId from openclaw's execute(toolCallId, ...) first
  arg (was previously discarded as _id).

Cross-runtime contract: tool name, input schema, return shape, and
sentinel prefix ("[trimmed by self] ") match Plexum's dynamic-trim
in internal/dynmem/trim.go + internal/persistence/trim.go.

Sim e2e tested: dynamic-trim queues, agent_end drain rewrites both
the target tool_result content AND the trim call's tool_use input.
No takeover errors. trimmed_bytes positive on real workloads.

plugin/openclaw.plugin.json

@@ -10,8 +10,7 @@
       "pcexec",
       "proxy-pcexec",
       "safe_restart",
-      "trim-tool-result",
-      "list-tool-results"
+      "dynamic-trim"
     ]
   },
   "configSchema": {