feat: implement comprehensive query paradigm zoo system (issue #62)

- Created extensible BaseQueryParadigm interface with standardized QueryResult format
- Implemented QueryParadigmRegistry for paradigm discovery and management
- Added 5 working paradigms: SQL, FTS, GraphQL, JSONPath, Natural Language
- Documented 9 additional paradigms: QBE, Batch Manipulation, Visual Query Builder, REST API, NoSQL, UNIX Pipeline, XPath/XQuery, RAG, Data Transformation
- Integrated full CLI interface: list, search, show, exec, categories commands
- Added comprehensive test suite with 23 test cases covering all components
- Auto-registration system enables easy addition of new paradigms
- Organized paradigms by category (structural, textual, semantic, visual, procedural, network) and complexity (beginner, intermediate, advanced)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

markitect/query_paradigms/paradigms/visual_builder_paradigm.py

@@ -0,0 +1,135 @@
+"""
+Visual Query Builder Paradigm - Drag-and-drop query construction.
+"""
+
+import time
+from typing import Dict, Any, List, Optional
+
+from ..base import BaseQueryParadigm, QueryResult
+
+
+class VisualQueryBuilderParadigm(BaseQueryParadigm):
+    """Visual query builder paradigm for drag-and-drop query construction."""
+
+    @property
+    def name(self) -> str:
+        return "Visual Query Builder"
+
+    @property
+    def description(self) -> str:
+        return "Drag-and-drop interface for building complex queries visually, generates SQL/GraphQL automatically"
+
+    @property
+    def category(self) -> str:
+        return "visual"
+
+    @property
+    def complexity(self) -> str:
+        return "beginner"
+
+    def execute(self, query: str, config: Dict[str, Any] = None) -> QueryResult:
+        """Execute visual query (not yet implemented)."""
+        start_time = time.time()
+
+        # This is a documentation paradigm - not yet implemented
+        execution_time = (time.time() - start_time) * 1000
+
+        return QueryResult(
+            paradigm=self.name,
+            query=query,
+            execution_time_ms=execution_time,
+            result_count=0,
+            results=[],
+            metadata={
+                "status": "not_implemented",
+                "implementation_issue": "TBD - to be created",
+                "description": "Visual query builder provides drag-and-drop interface for constructing complex queries"
+            },
+            success=False,
+            error_message="Visual Query Builder paradigm not yet implemented. This paradigm will provide a web-based drag-and-drop interface."
+        )
+
+    def get_examples(self) -> List[Dict[str, str]]:
+        """Get example visual query configurations."""
+        return [
+            {
+                "name": "Simple filter",
+                "description": "Drag file table, add author filter",
+                "query": "{'tables': ['files'], 'filters': [{'field': 'author', 'operator': 'equals', 'value': 'Alice'}]}"
+            },
+            {
+                "name": "Join with aggregation",
+                "description": "Join files and tags, count by tag",
+                "query": "{'tables': ['files', 'tags'], 'joins': [{'type': 'inner', 'on': 'file_id'}], 'groupBy': ['tag_name'], 'aggregates': [{'function': 'count', 'field': '*'}]}"
+            },
+            {
+                "name": "Date range with sorting",
+                "description": "Files created in last month, sorted by date",
+                "query": "{'tables': ['files'], 'filters': [{'field': 'created_at', 'operator': 'greater_than', 'value': '30 days ago'}], 'orderBy': [{'field': 'created_at', 'direction': 'desc'}]}"
+            },
+            {
+                "name": "Complex multi-table",
+                "description": "Files with tags and author info, filtered by multiple criteria",
+                "query": "{'tables': ['files', 'tags', 'authors'], 'joins': [{'type': 'left', 'on': 'file_id'}, {'type': 'inner', 'on': 'author_id'}], 'filters': [{'field': 'tag_name', 'operator': 'in', 'value': ['documentation', 'tutorial']}, {'field': 'author.department', 'operator': 'equals', 'value': 'Engineering'}]}"
+            }
+        ]
+
+    def validate_query(self, query: str) -> tuple[bool, Optional[str]]:
+        """Validate visual query configuration."""
+        try:
+            import json
+            config = json.loads(query)
+
+            if not isinstance(config, dict):
+                return False, "Visual query configuration must be a JSON object"
+
+            if 'tables' not in config:
+                return False, "Visual query must specify at least one table"
+
+            if not isinstance(config['tables'], list) or len(config['tables']) == 0:
+                return False, "Tables must be a non-empty list"
+
+            return True, None
+        except json.JSONDecodeError:
+            return False, "Visual query configuration must be valid JSON"
+
+    def get_syntax_help(self) -> str:
+        """Get syntax help for visual query builder."""
+        return """Visual Query Builder Configuration:
+
+The visual query builder uses JSON configuration that represents the visual elements:
+
+Basic Structure:
+{
+  "tables": ["table1", "table2"],
+  "joins": [{"type": "inner|left|right", "on": "field_name"}],
+  "filters": [{"field": "field_name", "operator": "equals|contains|greater_than|in", "value": "value"}],
+  "groupBy": ["field1", "field2"],
+  "aggregates": [{"function": "count|sum|avg|min|max", "field": "field_name"}],
+  "orderBy": [{"field": "field_name", "direction": "asc|desc"}],
+  "limit": 100
+}
+
+Filter Operators:
+- equals: Exact match
+- contains: Text contains substring
+- greater_than, less_than: Numeric/date comparison
+- in: Value in list
+- between: Value between two values
+
+Aggregate Functions:
+- count: Count records
+- sum: Sum numeric values
+- avg: Average of numeric values
+- min/max: Minimum/maximum values
+
+Example:
+{
+  "tables": ["files"],
+  "filters": [
+    {"field": "author", "operator": "equals", "value": "Alice"},
+    {"field": "created_at", "operator": "greater_than", "value": "2024-01-01"}
+  ],
+  "orderBy": [{"field": "created_at", "direction": "desc"}]
+}
+"""