fix(ci): remove child.deinit() — std.process.Child has no deinit in Zig 0.15.2

PRs #171 and #172 added child.deinit() calls, but std.process.Child
doesn't have a deinit method. Builds locally due to lazy evaluation
but fails CI when tri-api is compiled.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Antigravity Agent

src/tri-api/mcp_client.zig

@@ -57,7 +57,6 @@ pub const McpManager = struct {
 
         child.spawn() catch |err| {
             std.debug.print("[mcp] Failed to spawn {s}: {s}\n", .{ name, @errorName(err) });
-            child.deinit();
             return 0;
         };
 

src/tri/tri_state.zig

@@ -33,7 +33,6 @@ pub fn runProcessAndCapture(allocator: std.mem.Allocator, argv: []const []const
 /// Run a subprocess, inherit stdio, return exit code
 pub fn runProcessInherit(allocator: std.mem.Allocator, argv: []const []const u8) !u8 {
     var child = std.process.Child.init(argv, allocator);
-    defer child.deinit();
     child.stdout_behavior = .Inherit;
     child.stderr_behavior = .Inherit;
     _ = try child.spawn();