remove tool_load: use ctl directly

tool_load was a built-in intercept in the agent loop — the only
'tool' that didn't run in toolsrv. Removed entirely:
- Intercept in loop.go (25 lines)
- Script + .meta in data/tools/
- autoLoad references in agent configs

Loading tools is now exclusively via ctl (which already existed):
  echo 'tool_load X' | ollie-9p write .../ctl

System prompt updated to show the ctl pattern.

cmd/olliesrv/internal/agent/loop.go

@@ -580,31 +580,6 @@ func (ag *Agent) execOne(ctx context.Context, call backend.ToolCall) (toolResult
 		return toolResult{ToolCallID: call.ID, Name: call.Name, Content: result, IsError: isErr}, false
 	}
 
-	// Built-in: tool_load - must be handled specially because tools run inside
-	// toolsrv and can't load other tools into themselves.
-	if call.Name == "tool_load" {
-		var args struct {
-			Name string `json:"name"`
-		}
-		if err := json.Unmarshal(call.Arguments, &args); err != nil {
-			result = "error: " + err.Error()
-			isErr = true
-		} else if args.Name == "" {
-			result = "error: name is required"
-			isErr = true
-		} else if toolServer == nil {
-			result = "error: no tool server"
-			isErr = true
-		} else if err := toolServer.LoadTool(args.Name); err != nil {
-			result = "error: " + err.Error()
-			isErr = true
-		} else {
-			result = "loaded: " + args.Name
-		}
-		ag.emit(Event{Role: "tool", Name: call.Name, Content: result, OutputFormat: toolOutputFormat(rt, call.Name)})
-		return toolResult{ToolCallID: call.ID, Name: call.Name, Content: result, IsError: isErr}, false
-	}
-
 	if rt.Exec != nil {
 		out, blocks, err := rt.Exec(ctx, call.Name, call.Arguments)
 		if err != nil {

cmd/olliesrv/internal/prompts/system_prompt.md

@@ -26,7 +26,13 @@ Proactively load what you need — don't wait to be told.
 
 ## Tools
 
-Tools are loaded at startup. Additional tools can be loaded at runtime via the `tool_load` tool. Once loaded, a tool is a first-class function — call it directly by name.
+Tools are loaded at startup. Additional tools can be loaded at runtime via ctl:
+
+```bash
+echo "tool_load file_read" | ollie-9p write session/$OLLIE_SESSION_ID/agent/$OLLIE_UNAME/ctl
+```
+
+Once loaded, a tool is a first-class function — call it directly by name.
 
 **Important**: Use native tool calls, not shell. For example:
 - To read a file: call `file_read` directly, NOT `cat` or `shell` with any command
@@ -116,7 +122,7 @@ Your world model is a 9P filesystem. Your session ID is `${OLLIE_SESSION_ID}`. U
 | `chat.raw`  | read  | Full conversation with block markers |
 | `statewait` | read  | Blocks until state changes; returns new value |
 | `cfg`       | r/w   | Agent config (key=value: backend, model, cwd, temperature, etc.) |
-| `ctl`       | rdwr  | Control: stop, compact, clear, inject, agent, model, tools, tool_load, cwd, name |
+| `ctl`       | rdwr  | Control: stop, compact, clear, inject, agent, model, tools, tool_load, tool_unload, cwd, name |
 | `stats`     | read  | Usage, cost, context size |
 | `tools`     | r/w   | Write: load tool by name. Read: list loaded tools. |
 | `proc/`     | dir   | Detached background processes |

data/agents/default.json

@@ -11,7 +11,6 @@
     "file_glob",
     "file_grep",
     "file_write",
-    "tool_load"
   ],
   "maxSteps": 25,
   "temperature": 0.5,

data/agents/theo.json

@@ -11,7 +11,6 @@
     "file_glob",
     "file_grep",
     "file_write",
-    "tool_load"
   ],
   "maxSteps": 30,
   "temperature": 0.3,

data/tools/tool_load

@@ -1,20 +0,0 @@
-#!/bin/bash
-# args_json: {"type":"object","required":["name"],"properties":{"name":{"type":"string","description":"Tool name to load into the current session/agent"}}}
-# ollie:prompt
-# ## tool_load
-#
-# Load a tool into the current session/agent.
-#
-# **Args**: `name` (required) — the tool name to load.
-#
-# ```
-# tool_load(name="file_read")
-# ```
-# ollie:end
-
-set -euo pipefail
-
-# This tool just outputs the name - the actual loading is handled by
-# the agent framework when it receives the tool result.
-name=$(grep -oP '"name"\s*:\s*"\K[^"]+')
-echo "STATUS=ok TOOL_LOAD=$name"

data/tools/tool_load.meta

@@ -1,18 +0,0 @@
-{
-  "description": "Load a tool into the current session/agent via ollie-9p.",
-  "prompt": "## tool_load\n\nLoad a tool into the current session/agent by writing its name to\n`session/{sid}/agent/{aid}/tools` via ollie-9p.\n\n**Args**: `name` (required) — the tool name to load.\n\n```\ntool_load(name=\"file_read\")\n```",
-  "args": {
-    "type": "object",
-    "required": [
-      "name"
-    ],
-    "properties": {
-      "name": {
-        "type": "string",
-        "description": "Tool name to load into the current session/agent"
-      }
-    }
-  },
-  "tier": "hot",
-  "scope": "global"
-}