Add device management and database-backed desktop settings

This update migrates desktop grid settings from localStorage to the database
and introduces a comprehensive device management system.

Features:
- New haex_devices table for device identification and naming
- Device-specific settings with foreign key relationships
- Preset-based icon sizes (Small, Medium, Large, Extra Large)
- Grid positioning improvements to prevent dragging behind PageHeader
- Dynamic icon sizing based on database settings

Database Changes:
- Created haex_devices table with deviceId (UUID) and name columns
- Modified haex_settings to include device_id FK and updated unique constraint
- Migration 0002_loose_quasimodo.sql for schema changes

Technical Improvements:
- Replaced arbitrary icon size slider (60-200px) with preset system
- Icons use actual measured dimensions for proper grid centering
- Settings sync on vault mount for cross-device consistency
- Proper bounds checking during icon drag operations

Bump version to 0.1.7

src-tauri/database/migrations/0002_loose_quasimodo.sql

@@ -0,0 +1,13 @@
+CREATE TABLE `haex_devices` (
+	`id` text PRIMARY KEY NOT NULL,
+	`device_id` text NOT NULL,
+	`name` text NOT NULL,
+	`created_at` text DEFAULT (CURRENT_TIMESTAMP),
+	`updated_at` integer,
+	`haex_timestamp` text
+);
+--> statement-breakpoint
+CREATE UNIQUE INDEX `haex_devices_device_id_unique` ON `haex_devices` (`device_id`);--> statement-breakpoint
+DROP INDEX `haex_settings_key_type_value_unique`;--> statement-breakpoint
+ALTER TABLE `haex_settings` ADD `device_id` text REFERENCES haex_devices(id);--> statement-breakpoint
+CREATE UNIQUE INDEX `haex_settings_device_id_key_type_unique` ON `haex_settings` (`device_id`,`key`,`type`);