subagent_spawn: rewrite to use 9P agent/new rdwr

Replace D-Bus fire-and-forget with blocking ollie-9p rdwr to
agent/new. The tool now:
- Blocks until the sub-agent completes
- Returns the sub-agent's reply directly
- Scope: read (multiple spawns run in parallel)
- Tier: hot

Removed: D-Bus dependency, session renaming, JIT config cleanup.

data/tools/subagent_spawn

@@ -1,67 +1,45 @@
 #!/usr/bin/env bash
-# args_json: {"type":"object","required":["prompt"],"properties":{"prompt":{"type":"string","description":"Task prompt for the subagent"},"name":{"type":"string","description":"Subagent name (optional)"},"agent":{"type":"string","description":"Agent config (optional)"},"backend":{"type":"string","description":"Backend (optional)"},"model":{"type":"string","description":"Model (optional)"},"cwd":{"type":"string","description":"Working directory (optional)"}}}
+# args_json: {"type":"object","required":["prompt"],"properties":{"prompt":{"type":"string","description":"Task prompt for the subagent"},"name":{"type":"string","description":"Subagent display name (optional)"},"profile":{"type":"string","description":"Agent profile (optional, default: default)"},"backend":{"type":"string","description":"Backend (optional)"},"model":{"type":"string","description":"Model (optional)"},"cwd":{"type":"string","description":"Working directory (optional, default: current)"}}}
 # ollie:prompt
 # ## subagent_spawn
 #
-# Spawn an independent subagent session with a prompt. Returns immediately.
+# Spawn a sub-agent with a task. Blocks until the sub-agent completes and returns its reply.
+# The sub-agent gets its own context window and tool access. It is destroyed when done.
 #
 # ```
-# subagent_spawn(prompt="implement the login page", name="worker")
-# subagent_spawn(prompt="fix the tests in auth/")
+# subagent_spawn(prompt="fix the failing tests in auth/")
+# subagent_spawn(prompt="implement the login page", cwd="/home/user/project", model="sonnet")
 # ```
 #
-# **Returns**: session ID, backend, model.
+# Multiple subagent_spawn calls in the same turn run in parallel automatically.
 # ollie:end
+# ollie:scope read
+# ollie:tier hot
 set -euo pipefail
 
 source "$(dirname "$0")/_lib/args.sh"
 
-SERVICE="org.ollie.SessionManager"
-OBJ="/org/ollie/SessionManager"
-IFACE="org.ollie.SessionManager"
-
-die() { echo "error: $1" >&2; exit 1; }
-
-dbus_call() {
-    dbus-send --session --dest=$SERVICE --type=method_call --print-reply \
-        $OBJ "$IFACE.$1" "${@:2}" 2>/dev/null
-}
-
-dbus_string() {
-    dbus_call "$@" | awk -F'"' '/string "/{print $2; exit}'
-}
-
 prompt_text=$(arg_require "prompt")
-name=$(arg_get "name" "$(/bin/date +%s%N)-$$")
-agent=$(arg_get "agent" "default")
+name=$(arg_get "name" "")
+profile=$(arg_get "profile" "default")
 backend=$(arg_get "backend" "")
 model=$(arg_get "model" "")
 cwd=$(arg_get "cwd" "$(pwd)")
 
-# Prefix with parent session ID for global uniqueness.
-[ -n "${OLLIE_SESSION_ID:-}" ] && name="${OLLIE_SESSION_ID}__${name}"
+# Escape newlines in prompt for the key=value wire format.
+escaped_prompt=$(printf '%s' "$prompt_text" | sed 's/\\/\\\\/g; s/$/\\n/' | tr -d '\n' | sed 's/\\n$//')
 
-prompt="[parent_session_id=${OLLIE_SESSION_ID:-}]
-[session_id=${name}]
-${prompt_text}"
+# Build the payload.
+payload="cwd=${cwd}
+profile=${profile}
+prompt=${escaped_prompt}"
 
-# Create session via D-Bus
-session_id=$(dbus_string CreateSession \
-    string:"$cwd" string:"$backend" string:"$model" string:"$agent" string:"" string:"")
+[ -n "$name" ] && payload="${payload}
+name=${name}"
+[ -n "$backend" ] && payload="${payload}
+backend=${backend}"
+[ -n "$model" ] && payload="${payload}
+model=${model}"
 
-[ -z "$session_id" ] && die "failed to create session"
-
-# Rename to our chosen name
-dbus_call RenameSession string:"$session_id" string:"$name" > /dev/null 2>&1
-
-# Submit prompt
-dbus_call Submit string:"$session_id" string:"$prompt" > /dev/null 2>&1 || die "failed to submit prompt"
-
-# Clean up JIT agent config
-[[ "${agent:-}" == jit-* ]] && rm -f "$HOME/.config/ollie/agents/${agent}.json" 2>/dev/null || true
-
-# Report resolved values
-config=$(dbus_string GetConfig string:"$session_id")
-resolved_backend=$(printf '%s\n' "$config" | grep -m1 '^backend=' | cut -d= -f2- || echo "${backend:-default}")
-resolved_model=$(printf '%s\n' "$config" | grep -m1 '^model=' | cut -d= -f2- || echo "${model:-default}")
-printf 'session=%s\nbackend=%s\nmodel=%s\n' "$name" "$resolved_backend" "$resolved_model"
+# rdwr to agent/new: blocks until sub-agent completes, returns reply.
+printf '%s\n' "$payload" | ollie-9p rdwr "session/${OLLIE_SESSION_ID}/agent/new"

data/tools/subagent_spawn.meta

@@ -1,6 +1,8 @@
 {
-  "description": "Spawn an independent subagent session with a prompt. Returns immediately.",
-  "prompt": "## subagent_spawn\n\nSpawn an independent subagent session with a prompt. Returns immediately.\n\n```\nsubagent_spawn(prompt=\"implement the login page\", name=\"worker\")\nsubagent_spawn(prompt=\"fix the tests in auth/\")\n```\n\n**Returns**: session ID, backend, model.",
+  "description": "Spawn a sub-agent with a task. Blocks until done, returns the reply.",
+  "prompt": "## subagent_spawn\n\nSpawn a sub-agent with a task. Blocks until the sub-agent completes and returns its reply.\nThe sub-agent gets its own context window and tool access. It is destroyed when done.\n\n```\nsubagent_spawn(prompt=\"fix the failing tests in auth/\")\nsubagent_spawn(prompt=\"implement the login page\", cwd=\"/home/user/project\", model=\"sonnet\")\n```\n\nMultiple subagent_spawn calls in the same turn run in parallel automatically.",
+  "scope": "read",
+  "tier": "hot",
   "args": {
     "type": "object",
     "required": [
@@ -13,11 +15,11 @@
       },
       "name": {
         "type": "string",
-        "description": "Subagent name (optional)"
+        "description": "Subagent display name (optional)"
       },
-      "agent": {
+      "profile": {
         "type": "string",
-        "description": "Agent config (optional)"
+        "description": "Agent profile (optional, default: default)"
       },
       "backend": {
         "type": "string",
@@ -29,7 +31,7 @@
       },
       "cwd": {
         "type": "string",
-        "description": "Working directory (optional)"
+        "description": "Working directory (optional, default: current)"
       }
     }
   }