feat(cli): implement proper JSON parsing for sync progress

Use utils/json.zig helpers to parse sync progress messages:
- Add json module import
- Rename json variable to json_mode to avoid shadowing
- Parse status, progress, total fields from JSON response
- Show percentage completion for in-progress syncs
- Handle 'complete' and 'error' status codes

Build verified: zig build --release=fast

cli/src/commands/sync.zig

@@ -5,6 +5,7 @@ const crypto = @import("../utils/crypto.zig");
 const rsync = @import("../utils/rsync_embedded.zig");
 const ws = @import("../net/ws/client.zig");
 const logging = @import("../utils/logging.zig");
+const json = @import("../utils/json.zig");
 
 pub fn run(allocator: std.mem.Allocator, args: []const []const u8) !void {
     if (args.len == 0) {
@@ -24,7 +25,7 @@ pub fn run(allocator: std.mem.Allocator, args: []const []const u8) !void {
     var job_name: ?[]const u8 = null;
     var should_queue = false;
     var priority: u8 = 5;
-    var json: bool = false;
+    var json_mode: bool = false;
 
     // Parse flags
     var i: usize = 1;
@@ -35,7 +36,7 @@ pub fn run(allocator: std.mem.Allocator, args: []const []const u8) !void {
         } else if (std.mem.eql(u8, args[i], "--queue")) {
             should_queue = true;
         } else if (std.mem.eql(u8, args[i], "--json")) {
-            json = true;
+            json_mode = true;
         } else if (std.mem.eql(u8, args[i], "--priority") and i + 1 < args.len) {
             priority = try std.fmt.parseInt(u8, args[i + 1], 10);
             i += 1;
@@ -63,7 +64,7 @@ pub fn run(allocator: std.mem.Allocator, args: []const []const u8) !void {
     // Sync using embedded rsync (no external binary needed)
     try rsync.sync(allocator, path, remote_path, config.worker_port);
 
-    if (json) {
+    if (json_mode) {
         std.debug.print("{\"ok\":true,\"action\":\"sync\",\"commit_id\":\"{s}\"}\n", .{commit_id});
     } else {
         colors.printSuccess("✓ Files synced to server\n", .{});
@@ -140,10 +141,34 @@ fn monitorSyncProgress(allocator: std.mem.Allocator, config: *const Config, comm
         };
         defer allocator.free(message);
 
-        // For now, just display a simple success message
-        // TODO: Implement proper JSON parsing and packet handling
-        logging.success("Sync progress message received\n", .{});
-        break;
+        // Parse JSON progress message using shared utilities
+        const parsed = std.json.parseFromSlice(std.json.Value, allocator, message, .{}) catch {
+            logging.success("Sync progress: {s}\n", .{message});
+            break;
+        };
+        defer parsed.deinit();
+
+        if (parsed.value == .object) {
+            const root = parsed.value.object;
+            const status = json.getString(root, "status") orelse "unknown";
+            const progress = json.getInt(root, "progress") orelse 0;
+            const total = json.getInt(root, "total") orelse 0;
+
+            if (std.mem.eql(u8, status, "complete")) {
+                logging.success("Sync complete!\n", .{});
+                break;
+            } else if (std.mem.eql(u8, status, "error")) {
+                const error_msg = json.getString(root, "error") orelse "Unknown error";
+                logging.err("Sync failed: {s}\n", .{error_msg});
+                return error.SyncFailed;
+            } else {
+                const pct = if (total > 0) @divTrunc(progress * 100, total) else 0;
+                logging.progress("Sync: {s} ({d}/{d} files, {d}%)\n", .{ status, progress, total, pct });
+            }
+        } else {
+            logging.success("Sync progress: {s}\n", .{message});
+            break;
+        }
     }
 
     if (timeout_counter >= max_timeout) {