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>

backend/app/schemas/__init__.py

@@ -10,6 +10,11 @@ from .ai_builder import (
     AIStartResponse, AIScaffoldResponse, AIBranchDetailResponse, AIAssembleResponse,
     AIQuotaStatusResponse,
 )
+from .script_template import (
+    ScriptCategoryResponse,
+    ScriptTemplateCreate, ScriptTemplateUpdate, ScriptTemplateListItem, ScriptTemplateDetail,
+    ScriptGenerateRequest, ScriptGenerateResponse, ScriptGenerationRecord,
+)
 
 __all__ = [
     # User
@@ -30,4 +35,8 @@ __all__ = [
     "AIStartRequest", "AIScaffoldRequest", "AIBranchDetailRequest", "AIAssembleRequest",
     "AIStartResponse", "AIScaffoldResponse", "AIBranchDetailResponse", "AIAssembleResponse",
     "AIQuotaStatusResponse",
+    # Script Generator
+    "ScriptCategoryResponse",
+    "ScriptTemplateCreate", "ScriptTemplateUpdate", "ScriptTemplateListItem", "ScriptTemplateDetail",
+    "ScriptGenerateRequest", "ScriptGenerateResponse", "ScriptGenerationRecord",
 ]