Add snippet/command library with CRUD and send-to-session

Full command snippet library for saving and sending reusable commands:

Backend:
- SQLite migration 003 creates snippets table
- Snippet model with name, command, description, folder, tags
- Store CRUD methods and API endpoints

Frontend:
- SnippetLibrary class with searchable list + detail/editor split view
- Create, edit, delete snippets in modal dialog
- 'Send to Session' button writes command to active terminal
- 'Send Snippet' option in terminal right-click context menu
- Ctrl+Shift+S keyboard shortcut to open library

frontend/wailsjs/go/api/Service.d.ts

@@ -17,6 +17,8 @@ export function ConnectSession(arg1:string):Promise<models.SessionInfo>;
 
 export function CreateProfile(arg1:models.Profile):Promise<models.Profile>;
 
+export function CreateSnippet(arg1:models.Snippet):Promise<models.Snippet>;
+
 export function DeleteKnownHost(arg1:string):Promise<void>;
 
 export function DeleteProfile(arg1:string):Promise<void>;
@@ -25,6 +27,8 @@ export function DeleteProfileSecrets(arg1:string):Promise<void>;
 
 export function DeleteRecording(arg1:string):Promise<void>;
 
+export function DeleteSnippet(arg1:string):Promise<void>;
+
 export function DisconnectSession(arg1:string):Promise<void>;
 
 export function DuplicateProfile(arg1:string):Promise<models.Profile>;
@@ -77,6 +81,8 @@ export function ListRecordings():Promise<Array<Record<string, any>>>;
 
 export function ListSessions():Promise<Array<models.SessionInfo>>;
 
+export function ListSnippets():Promise<Array<models.Snippet>>;
+
 export function LockSecretStore():Promise<void>;
 
 export function NewProfile(arg1:string):Promise<models.Profile>;
@@ -139,6 +145,8 @@ export function UnlockSecretStore(arg1:string):Promise<void>;
 
 export function UpdateProfile(arg1:models.Profile):Promise<models.Profile>;
 
+export function UpdateSnippet(arg1:models.Snippet):Promise<models.Snippet>;
+
 export function WriteSession(arg1:string,arg2:string):Promise<void>;
 
 export function WriteSessionEscaped(arg1:string,arg2:string):Promise<void>;