Add /diff and /template commands

- /diff command to compare config with backups
  - Shows added/removed/changed files
  - JSON-aware comparison for config files
  - List available backups
- /template command for session templates
  - Built-in templates: daily-standup, code-review, troubleshoot, deploy
  - Each template includes checklist, initial commands, prompt
  - Create custom templates interactively or non-interactively
- Updated shell completions with 21 aliases total
- Test suite now covers 29 tests

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

commands/template.md

@@ -0,0 +1,44 @@
+---
+name: template
+description: Manage session templates for common workflows
+aliases: [templates, session-template]
+invokes: command:template
+---
+
+# Template Command
+
+Create and use session templates for repeatable workflows.
+
+## Usage
+
+```
+/template                   # List all templates
+/template --use <name>      # Display template for use
+/template --create <name>   # Create new template
+/template --delete <name>   # Delete a template
+```
+
+## Implementation
+
+```bash
+python3 ~/.claude/automation/session-template.py [options]
+```
+
+## Built-in Templates
+
+| Name | Category | Description |
+|------|----------|-------------|
+| `daily-standup` | routine | Morning status check and planning |
+| `code-review` | development | Review code changes in a project |
+| `troubleshoot` | debugging | Debug an issue systematically |
+| `deploy` | operations | Deploy application to environment |
+
+## Template Contents
+
+Each template includes:
+- **Description** - What the template is for
+- **Category** - Grouping for organization
+- **Context level** - How much context to gather
+- **Initial commands** - Commands to run at start
+- **Checklist** - Steps to follow
+- **Prompt template** - Suggested starting prompt