feat(api, web): implement short install link functionality for agents

- Added new API endpoints for creating, retrieving, and revoking install links for agents.
- Enhanced the agent installation process with short links accessible via `/agent-install/:id` and `/:slug`.
- Updated the README and documentation to reflect the new installation method and usage instructions.
- Refactored relevant components in the web application to support the new install link feature.
- Improved error handling and validation for install link operations.

Co-authored-by: Cursor <[email protected]>

packages/db/migrations/003_install_links.sql

@@ -0,0 +1,19 @@
+-- Agent install short-links (one-liner invites)
+
+CREATE TABLE IF NOT EXISTS agent_install_links (
+  id TEXT PRIMARY KEY,
+  slug TEXT NOT NULL UNIQUE,
+  client_name TEXT NOT NULL,
+  platform TEXT NOT NULL DEFAULT 'linux',
+  created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
+  revoked_at TEXT,
+  last_used_at TEXT,
+  use_count INTEGER NOT NULL DEFAULT 0,
+  CHECK (platform IN ('linux', 'mikrotik')),
+  CHECK (length(trim(client_name)) > 0),
+  CHECK (length(trim(id)) > 0),
+  CHECK (length(trim(slug)) > 0)
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS idx_agent_install_links_slug
+  ON agent_install_links (slug);