feat(tagged-tasks): Complete core tag management system implementation

- Implements comprehensive tagged task lists system for multi-context task management including core tag management functions (Task 103.11), MCP integration updates, and foundational infrastructure for tagged task operations. Features tag CRUD operations, validation, metadata tracking, deep task copying, and full backward compatibility.

scripts/modules/ui.js

@@ -659,6 +659,42 @@ function displayHelp() {
 				}
 			]
 		},
+		{
+			title: 'Tag Management',
+			color: 'magenta',
+			commands: [
+				{
+					name: 'tags',
+					args: '[--show-metadata]',
+					desc: 'List all available tags with task counts'
+				},
+				{
+					name: 'add-tag',
+					args: '<tagName> [--copy-from-current] [--copy-from=<tag>] [-d="<desc>"]',
+					desc: 'Create a new tag context for organizing tasks'
+				},
+				{
+					name: 'use-tag',
+					args: '<tagName>',
+					desc: 'Switch to a different tag context'
+				},
+				{
+					name: 'delete-tag',
+					args: '<tagName> [--yes]',
+					desc: 'Delete an existing tag and all its tasks'
+				},
+				{
+					name: 'rename-tag',
+					args: '<oldName> <newName>',
+					desc: 'Rename an existing tag'
+				},
+				{
+					name: 'copy-tag',
+					args: '<sourceName> <targetName> [-d="<desc>"]',
+					desc: 'Copy an existing tag to create a new tag with the same tasks'
+				}
+			]
+		},
 		{
 			title: 'Dependency Management',
 			color: 'blue',