feat(processes): monospace prompt editor for note_type=process

Task 6 of #582. NoteType gains 'process'. NoteEditorView branches to a plain
monospace textarea (labeled Prompt) for processes instead of the TipTap
rich-text editor — prompts are plain markdown and rich-text round-tripping
would mangle them. Title/tags/save path unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/types/note.ts

@@ -1,6 +1,6 @@
 export type TaskStatus = "todo" | "in_progress" | "done" | "cancelled";
 export type TaskPriority = "none" | "low" | "medium" | "high";
-export type NoteType = "note" | "person" | "place" | "list";
+export type NoteType = "note" | "person" | "place" | "list" | "process";
 
 export interface Note {
   id: number;

frontend/src/views/NoteEditorView.vue

@@ -130,6 +130,7 @@ const titlePlaceholder = computed(() => {
     case 'person': return 'Name';
     case 'place': return 'Place name';
     case 'list': return 'List title';
+    case 'process': return 'Process name';
     default: return 'Title';
   }
 });
@@ -602,6 +603,18 @@ onUnmounted(() => assist.clearSelection());
           </div>
         </template>
 
+        <!-- ── Process (prompt) editor ──────────────────────────── -->
+        <template v-else-if="noteType === 'process'">
+          <label class="ef-label">Prompt</label>
+          <textarea
+            class="prompt-editor"
+            :value="body"
+            @input="onBodyUpdate(($event.target as HTMLTextAreaElement).value)"
+            placeholder="The prompt to run when this process is fired (markdown). If it needs inputs, instruct Claude to ask up front."
+            spellcheck="false"
+          ></textarea>
+        </template>
+
         <!-- ── Generic note editor ──────────────────────────────── -->
         <template v-else>
           <div class="body-tabs-row">
@@ -1038,6 +1051,26 @@ onUnmounted(() => assist.clearSelection());
   font-size: 0.92rem;
   color: var(--color-primary);
 }
+.prompt-editor {
+  width: 100%;
+  min-height: 60vh;
+  margin-top: 8px;
+  padding: 14px 16px;
+  border: 1px solid var(--color-border);
+  border-radius: 8px;
+  background: var(--color-surface);
+  color: var(--color-text);
+  /* Prompts are plain markdown — a code-style editor, not rich text. */
+  font-family: var(--font-mono, ui-monospace, SFMono-Regular, Menlo, Consolas, monospace);
+  font-size: 0.88rem;
+  line-height: 1.55;
+  tab-size: 2;
+  resize: vertical;
+  outline: none;
+}
+.prompt-editor:focus {
+  border-color: var(--color-primary);
+}
 .ef-input {
   padding: 8px 12px;
   border: 1px solid var(--color-border);