Add SDK usage examples

12 examples showing increasing levels of customization:
- 01-minimal: all defaults
- 02-custom-model: model and thinking level
- 03-custom-prompt: replace or modify prompt
- 04-skills: discover, filter, merge skills
- 05-tools: built-in tools, custom tools
- 06-hooks: logging, blocking, result modification
- 07-context-files: AGENTS.md files
- 08-slash-commands: file-based commands
- 09-api-keys-and-oauth: API key resolution, OAuth config
- 10-settings: compaction, retry, terminal settings
- 11-sessions: persistence options
- 12-full-control: replace everything

Also exports FileSlashCommand type from index.ts

packages/coding-agent/src/index.ts

@@ -103,6 +103,7 @@ export {
 	discoverModels,
 	discoverSkills,
 	discoverSlashCommands,
+	type FileSlashCommand,
 	findModel as findModelByProviderAndId,
 	loadSettings,
 	// Tools