feat: Add zap command for sending Bitcoin Lightning tips

- Implemented the `zap` command in the CLI to allow users to send sats to a user, event, or snippet using a NIP-60 wallet.
- Created a new `zap.ts` file to handle the command logic and integrated it into the MCP server.
- Added wallet balance command to check the balance of a user's wallet.
- Enhanced the MCP server to register the new zap command and wallet balance command.
- Introduced caching for wallets to optimize performance and reduce redundant network requests.
- Updated database schema to include snippets table for storing code snippets.
- Improved logging functionality for better debugging and tracking of operations.
- Added functionality to save snippets to the database upon retrieval.
- Updated project overview documentation to reflect new features and structure.
- Refactored existing commands and logic for better modularity and maintainability.

migrations/003-create-snippets-table.ts

@@ -0,0 +1,26 @@
+import type { Database } from "bun:sqlite";
+
+export async function up(db: Database): Promise<void> {
+    db.run(`
+        CREATE TABLE IF NOT EXISTS snippets (
+            id TEXT PRIMARY KEY NOT NULL,      -- Nostr event ID
+            title TEXT NOT NULL,
+            description TEXT NOT NULL,
+            code TEXT NOT NULL,
+            language TEXT NOT NULL,
+            pubkey TEXT NOT NULL,              -- Author's pubkey
+            createdAt INTEGER NOT NULL,        -- Unix timestamp
+            tags TEXT NOT NULL                 -- JSON string array of tags
+        )
+    `);
+
+    // Optional: Add indexes for frequently queried columns
+    db.run('CREATE INDEX IF NOT EXISTS idx_snippets_pubkey ON snippets (pubkey)');
+    db.run('CREATE INDEX IF NOT EXISTS idx_snippets_language ON snippets (language)');
+    db.run('CREATE INDEX IF NOT EXISTS idx_snippets_createdAt ON snippets (createdAt)');
+}
+
+
+export async function down(db: Database): Promise<void> {
+    db.run("DROP TABLE IF EXISTS snippets");
+}