feat: Maestro Mode - context-aware prompt generation

- Backend: POST /api/text-gen/maestro endpoint with dual modes
  - Empty prompt → generate from scratch (temp 1.0)
  - Non-empty prompt → complete/extend (temp 0.85)
  - structured=true → returns JSON fields for Advanced/Pro mode
  - Three system prompts: MAESTRO_GENERATE, MAESTRO_COMPLETE, MAESTRO_STRUCTURED
  - Trailing sentence cleanup for plain text mode
  - JSON fallback parsing for structured mode

- Frontend: MaestroButton component
  - Context-aware labels: ♪ Maestro Mode (empty) / ♪ Keep Composing (has content)
  - Loading states: animating ♩ with Dreaming.../Composing...
  - structured prop for Pro mode → populates structured fields
  - onStructuredResult callback merges fields into StructuredPrompt

- UX: Replaced 'Get Suggestions ✨' with Maestro Mode
  - Suggestions required text in the box; Maestro works with or without
  - Single button, context-aware behavior, cleaner UI
  - Advanced/Pro mode gets structured fields from Maestro
  - Removed SuggestionsModal dependency

- Rename: 'Compose for Me' → 'Keep Composing'

frontend/src/components/Generator.tsx

@@ -1,6 +1,6 @@
 import { useState, useEffect } from 'react'
 import StructuredPromptEditor, { PromptStructure } from './StructuredPromptEditor'
-import SuggestionsModal from './SuggestionsModal'
+import MaestroButton from './MaestroButton'
 
 interface ModelInfo {
   name: string
@@ -24,7 +24,7 @@ export default function Generator({ onGenerate }: Props) {
   const [models, setModels] = useState<Record<string, ModelInfo>>({})
   const [promptMode, setPromptMode] = useState<PromptMode>('basic')
   const [structuredPrompt, setStructuredPrompt] = useState<PromptStructure>({})
-  const [suggestionsOpen, setSuggestionsOpen] = useState(false)
+
 
   useEffect(() => {
     fetch('/api/models')
@@ -185,14 +185,16 @@ export default function Generator({ onGenerate }: Props) {
           <div>
             <div className="flex items-center justify-between mb-1.5">
               <label className="text-xs text-kithara-muted">Prompt</label>
-              <button
-                type="button"
-                onClick={() => setSuggestionsOpen(true)}
-                disabled={!prompt.trim()}
-                className="text-xs text-kithara-accent hover:text-kithara-accent/80 transition-colors disabled:opacity-40"
-              >
-                Get Suggestions ✨
-              </button>
+              <MaestroButton
+                prompt={prompt}
+                onResult={(result, mode) => {
+                  setPrompt(result)
+                  if (mode === 'generate') {
+                    setError('')
+                  }
+                }}
+                onError={(msg) => setError(msg)}
+              />
             </div>
             <textarea
               value={prompt}
@@ -208,14 +210,26 @@ export default function Generator({ onGenerate }: Props) {
           <div>
             <div className="flex items-center justify-between mb-1.5">
               <label className="text-xs text-kithara-muted">Structured Prompt</label>
-              <button
-                type="button"
-                onClick={() => setSuggestionsOpen(true)}
-                disabled={Object.values(structuredPrompt).every(v => !v?.trim())}
-                className="text-xs text-kithara-accent hover:text-kithara-accent/80 transition-colors disabled:opacity-40"
-              >
-                Get Suggestions ✨
-              </button>
+              <MaestroButton
+                prompt={Object.values(structuredPrompt).filter(Boolean).join(' ')}
+                structured={isPro}
+                onResult={(result, mode) => {
+                  // Fallback: plain text mode for non-Pro, put result in 'additional'
+                  setStructuredPrompt(prev => ({ ...prev, additional: result }))
+                  if (mode === 'generate') setError('')
+                }}
+                onStructuredResult={(fields, mode) => {
+                  // Structured mode: merge fields into structuredPrompt, preserving user edits
+                  setStructuredPrompt(prev => ({
+                    ...prev,
+                    ...Object.fromEntries(
+                      Object.entries(fields).filter(([_, v]) => v?.trim())
+                    ),
+                  }))
+                  if (mode === 'generate') setError('')
+                }}
+                onError={(msg) => setError(msg)}
+              />
             </div>
             <StructuredPromptEditor
               value={structuredPrompt}
@@ -237,19 +251,7 @@ export default function Generator({ onGenerate }: Props) {
         </button>
       </form>
 
-      <SuggestionsModal
-        isOpen={suggestionsOpen}
-        onClose={() => setSuggestionsOpen(false)}
-        onSelect={(suggestion) => {
-          if (promptMode === 'basic' || !isPro) {
-            setPrompt(suggestion)
-          } else {
-            // For advanced mode, put it in the 'style' field or additional
-            setStructuredPrompt(prev => ({ ...prev, additional: suggestion }))
-          }
-        }}
-        userInput={promptMode === 'basic' || !isPro ? prompt : Object.values(structuredPrompt).filter(Boolean).join(' ')}
-      />
+
     </div>
   )
 }