feat: Script Generator Phase 1+2 — backend, engine, API, frontend, template editor, parameter detector

Complete Script Generator feature including:

Backend:
- ScriptCategory, ScriptTemplate, ScriptGeneration models
- ScriptTemplateEngine with substitution, filters, sanitization
- CRUD + share API endpoints with permission checks
- Integration tests for permissions and sharing
- Migration 057 with AD User Management seed templates

Frontend — Script Library:
- Browse templates with category tabs and search
- Configure pane with parameter form and script generation
- Script preview with live substitution and copy/download
- scriptGeneratorStore Zustand store

Frontend — Template Editor:
- Full CRUD form with metadata, script body (Monaco Editor), parameters
- ParameterSchemaBuilder with visual builder + JSON toggle
- ScriptManagePage with routing and nav link

Frontend — Parameter Detector:
- Client-side PowerShell parameter detection engine
- Detects script-level param() blocks and variable assignments
- Type inference from PS type annotations and value patterns
- ParameterDetectorStepper one-by-one review UI with accept/skip

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/layout/Sidebar.tsx

@@ -1,5 +1,5 @@
 import { useEffect, useState } from 'react'
-import { LayoutGrid, Box, PenLine, Clock, FileText, Bookmark, BarChart3, Settings, PanelLeftClose, PanelLeftOpen, MessageSquareText, BotMessageSquare, BookOpen, Sparkles } from 'lucide-react'
+import { LayoutGrid, Box, PenLine, Clock, FileText, Bookmark, BarChart3, Settings, PanelLeftClose, PanelLeftOpen, MessageSquareText, BotMessageSquare, BookOpen, Sparkles, Terminal } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { useUserPreferencesStore } from '@/store/userPreferencesStore'
 import { usePinnedFlowsStore } from '@/store/pinnedFlowsStore'
@@ -83,6 +83,7 @@ export function Sidebar() {
             <NavItem href="/shares" icon={FileText} label="Exports" collapsed />
             <NavItem href="/assistant" icon={BotMessageSquare} label="AI Assistant" collapsed />
             <NavItem href="/step-library" icon={Bookmark} label="Step Library" collapsed />
+            <NavItem href="/scripts" icon={Terminal} label="Script Library" collapsed />
             <NavItem href="/kb-accelerator" icon={Sparkles} label="KB Accelerator" collapsed />
             <NavItem href="/analytics" icon={BarChart3} label="Analytics" collapsed />
             <NavItem href="/guides" icon={BookOpen} label="User Guides" collapsed />
@@ -116,6 +117,7 @@ export function Sidebar() {
             <NavItem href="/shares" icon={FileText} label="Exports" />
             <NavItem href="/assistant" icon={BotMessageSquare} label="AI Assistant" />
             <NavItem href="/step-library" icon={Bookmark} label="Step Library" />
+            <NavItem href="/scripts" icon={Terminal} label="Script Library" />
             <NavItem href="/kb-accelerator" icon={Sparkles} label="KB Accelerator" />
             <NavItem href="/analytics" icon={BarChart3} label="Analytics" />
           </div>