fix: vendor deps and fix CI go-version, timeout, GOTOOLCHAIN (HAN-414)

- Run go mod vendor to eliminate proxy.golang.org network dependency
- Set GOFLAGS=-mod=vendor at job env level so all go commands use vendor/
- Fix go-version from 1.23 to 1.24.0 to match go.mod
- Move GOTOOLCHAIN=local to job-level env (not per-step inline)
- Set cache: false on setup-go (cache is irrelevant with vendoring)
- Add timeout-minutes: 15 so failures are caught quickly instead of 3h

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: multica-agent <github@multica.ai>

vendor/golang.org/x/sys/windows/mkknownfolderids.bash

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+# Copyright 2019 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+set -e
+shopt -s nullglob
+
+knownfolders="$(printf '%s\n' "/mnt/c/Program Files (x86)/Windows Kits/"/*/Include/*/um/KnownFolders.h | sort -Vr | head -n 1)"
+[[ -n $knownfolders ]] || { echo "Unable to find KnownFolders.h" >&2; exit 1; }
+
+{
+	echo "// Code generated by 'mkknownfolderids.bash'; DO NOT EDIT."
+	echo
+	echo "package windows"
+	echo "type KNOWNFOLDERID GUID"
+	echo "var ("
+	while read -r line; do
+		[[ $line =~ DEFINE_KNOWN_FOLDER\((FOLDERID_[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+),[\t\ ]*(0x[^,]+)\) ]] || continue
+		printf "%s = &KNOWNFOLDERID{0x%08x, 0x%04x, 0x%04x, [8]byte{0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x, 0x%02x}}\n" \
+			"${BASH_REMATCH[1]}" $(( "${BASH_REMATCH[2]}" )) $(( "${BASH_REMATCH[3]}" )) $(( "${BASH_REMATCH[4]}" )) \
+			$(( "${BASH_REMATCH[5]}" )) $(( "${BASH_REMATCH[6]}" )) $(( "${BASH_REMATCH[7]}" )) $(( "${BASH_REMATCH[8]}" )) \
+			$(( "${BASH_REMATCH[9]}" )) $(( "${BASH_REMATCH[10]}" )) $(( "${BASH_REMATCH[11]}" )) $(( "${BASH_REMATCH[12]}" ))
+	done < "$knownfolders"
+	echo ")"
+} | gofmt > "zknownfolderids_windows.go"