agents: move user-preferences to userPrompts

user-preferences.md is meant to be prepended to every user message,
not part of the system prompt. Moved from 'prompt' to 'userPrompts'
in: author, conductor, default, foreman, panelist, reviewer.

Other agents already had it in the correct location.

data/agents/author.json

@@ -1,6 +1,8 @@
 {
   "prompt": [
-    "$XDG_CONFIG_HOME/ollie/prompts/agent-author.md",
+    "$XDG_CONFIG_HOME/ollie/prompts/agent-author.md"
+  ],
+  "userPrompts": [
     "$XDG_CONFIG_HOME/ollie/prompts/user-preferences.md"
   ],
   "autoLoad": [

data/agents/conductor.json

@@ -1,6 +1,8 @@
 {
   "prompt": [
-    "$XDG_CONFIG_HOME/ollie/prompts/agent-conductor.md",
+    "$XDG_CONFIG_HOME/ollie/prompts/agent-conductor.md"
+  ],
+  "userPrompts": [
     "$XDG_CONFIG_HOME/ollie/prompts/user-preferences.md"
   ],
   "autoLoad": [

data/agents/default.json

@@ -1,8 +1,10 @@
 {
   "prompt": [
-    "$XDG_CONFIG_HOME/ollie/prompts/user-preferences.md",
     "$XDG_CONFIG_HOME/ollie/prompts/agent-coding.md"
   ],
+  "userPrompts": [
+    "$XDG_CONFIG_HOME/ollie/prompts/user-preferences.md"
+  ],
   "autoLoad": [
     "shell",
     "reasoning_think",

data/agents/foreman.json

@@ -1,6 +1,8 @@
 {
   "prompt": [
-    "$XDG_CONFIG_HOME/ollie/prompts/agent-foreman.md",
+    "$XDG_CONFIG_HOME/ollie/prompts/agent-foreman.md"
+  ],
+  "userPrompts": [
     "$XDG_CONFIG_HOME/ollie/prompts/user-preferences.md"
   ],
   "autoLoad": [

data/agents/panelist.json

@@ -1,6 +1,8 @@
 {
   "prompt": [
-    "$XDG_CONFIG_HOME/ollie/prompts/agent-panelist.md",
+    "$XDG_CONFIG_HOME/ollie/prompts/agent-panelist.md"
+  ],
+  "userPrompts": [
     "$XDG_CONFIG_HOME/ollie/prompts/user-preferences.md"
   ],
   "autoLoad": [

data/agents/reviewer.json

@@ -1,6 +1,8 @@
 {
   "prompt": [
-    "$XDG_CONFIG_HOME/ollie/prompts/agent-reviewer.md",
+    "$XDG_CONFIG_HOME/ollie/prompts/agent-reviewer.md"
+  ],
+  "userPrompts": [
     "$XDG_CONFIG_HOME/ollie/prompts/user-preferences.md"
   ],
   "autoLoad": [