feat: migrate from Cedar to SpiceDB authorization system

This is a major architectural change that replaces the Cedar policy-based
authorization system with SpiceDB's relation-based authorization.

Key changes:

- Migrate from Rust to Go implementation
- Replace Cedar policies with SpiceDB schema and relationships
- Switch from envoy `ext_authz` with Cedar to SpiceDB permission checks
- Update build system and dependencies for Go ecosystem
- Maintain Envoy integration for external authorization

This change enables more flexible permission modeling through SpiceDB's
Google Zanzibar inspired relation-based system, supporting complex
hierarchical permissions that were difficult to express in Cedar.

Breaking change: Existing Cedar policies and Rust-based configuration
will no longer work and need to be migrated to SpiceDB schema.

10 files changed, 299 insertions, 0 deletions

diff --git a/vendor/github.com/mattn/go-isatty/LICENSE b/vendor/github.com/mattn/go-isatty/LICENSE
new file mode 100644
index 00000000..65dc692b
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/LICENSE
@@ -0,0 +1,9 @@
+Copyright (c) Yasuhiro MATSUMOTO <mattn.jp@gmail.com>
+
+MIT License (Expat)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/github.com/mattn/go-isatty/README.md b/vendor/github.com/mattn/go-isatty/README.md
new file mode 100644
index 00000000..38418353
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/README.md
@@ -0,0 +1,50 @@
+# go-isatty
+
+[![Godoc Reference](https://godoc.org/github.com/mattn/go-isatty?status.svg)](http://godoc.org/github.com/mattn/go-isatty)
+[![Codecov](https://codecov.io/gh/mattn/go-isatty/branch/master/graph/badge.svg)](https://codecov.io/gh/mattn/go-isatty)
+[![Coverage Status](https://coveralls.io/repos/github/mattn/go-isatty/badge.svg?branch=master)](https://coveralls.io/github/mattn/go-isatty?branch=master)
+[![Go Report Card](https://goreportcard.com/badge/mattn/go-isatty)](https://goreportcard.com/report/mattn/go-isatty)
+
+isatty for golang
+
+## Usage
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/mattn/go-isatty"
+	"os"
+)
+
+func main() {
+	if isatty.IsTerminal(os.Stdout.Fd()) {
+		fmt.Println("Is Terminal")
+	} else if isatty.IsCygwinTerminal(os.Stdout.Fd()) {
+		fmt.Println("Is Cygwin/MSYS2 Terminal")
+	} else {
+		fmt.Println("Is Not Terminal")
+	}
+}
+```
+
+## Installation
+
+```
+$ go get github.com/mattn/go-isatty
+```
+
+## License
+
+MIT
+
+## Author
+
+Yasuhiro Matsumoto (a.k.a mattn)
+
+## Thanks
+
+* k-takata: base idea for IsCygwinTerminal
+
+    https://github.com/k-takata/go-iscygpty
diff --git a/vendor/github.com/mattn/go-isatty/doc.go b/vendor/github.com/mattn/go-isatty/doc.go
new file mode 100644
index 00000000..17d4f90e
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/doc.go
@@ -0,0 +1,2 @@
+// Package isatty implements interface to isatty
+package isatty
diff --git a/vendor/github.com/mattn/go-isatty/go.test.sh b/vendor/github.com/mattn/go-isatty/go.test.sh
new file mode 100644
index 00000000..012162b0
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/go.test.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+set -e
+echo "" > coverage.txt
+
+for d in $(go list ./... | grep -v vendor); do
+    go test -race -coverprofile=profile.out -covermode=atomic "$d"
+    if [ -f profile.out ]; then
+        cat profile.out >> coverage.txt
+        rm profile.out
+    fi
+done
diff --git a/vendor/github.com/mattn/go-isatty/isatty_bsd.go b/vendor/github.com/mattn/go-isatty/isatty_bsd.go
new file mode 100644
index 00000000..d0ea68f4
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/isatty_bsd.go
@@ -0,0 +1,20 @@
+//go:build (darwin || freebsd || openbsd || netbsd || dragonfly || hurd) && !appengine && !tinygo
+// +build darwin freebsd openbsd netbsd dragonfly hurd
+// +build !appengine
+// +build !tinygo
+
+package isatty
+
+import "golang.org/x/sys/unix"
+
+// IsTerminal return true if the file descriptor is terminal.
+func IsTerminal(fd uintptr) bool {
+	_, err := unix.IoctlGetTermios(int(fd), unix.TIOCGETA)
+	return err == nil
+}
+
+// IsCygwinTerminal return true if the file descriptor is a cygwin or msys2
+// terminal. This is also always false on this environment.
+func IsCygwinTerminal(fd uintptr) bool {
+	return false
+}
diff --git a/vendor/github.com/mattn/go-isatty/isatty_others.go b/vendor/github.com/mattn/go-isatty/isatty_others.go
new file mode 100644
index 00000000..7402e061
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/isatty_others.go
@@ -0,0 +1,17 @@
+//go:build (appengine || js || nacl || tinygo || wasm) && !windows
+// +build appengine js nacl tinygo wasm
+// +build !windows
+
+package isatty
+
+// IsTerminal returns true if the file descriptor is terminal which
+// is always false on js and appengine classic which is a sandboxed PaaS.
+func IsTerminal(fd uintptr) bool {
+	return false
+}
+
+// IsCygwinTerminal() return true if the file descriptor is a cygwin or msys2
+// terminal. This is also always false on this environment.
+func IsCygwinTerminal(fd uintptr) bool {
+	return false
+}
diff --git a/vendor/github.com/mattn/go-isatty/isatty_plan9.go b/vendor/github.com/mattn/go-isatty/isatty_plan9.go
new file mode 100644
index 00000000..bae7f9bb
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/isatty_plan9.go
@@ -0,0 +1,23 @@
+//go:build plan9
+// +build plan9
+
+package isatty
+
+import (
+	"syscall"
+)
+
+// IsTerminal returns true if the given file descriptor is a terminal.
+func IsTerminal(fd uintptr) bool {
+	path, err := syscall.Fd2path(int(fd))
+	if err != nil {
+		return false
+	}
+	return path == "/dev/cons" || path == "/mnt/term/dev/cons"
+}
+
+// IsCygwinTerminal return true if the file descriptor is a cygwin or msys2
+// terminal. This is also always false on this environment.
+func IsCygwinTerminal(fd uintptr) bool {
+	return false
+}
diff --git a/vendor/github.com/mattn/go-isatty/isatty_solaris.go b/vendor/github.com/mattn/go-isatty/isatty_solaris.go
new file mode 100644
index 00000000..0c3acf2d
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/isatty_solaris.go
@@ -0,0 +1,21 @@
+//go:build solaris && !appengine
+// +build solaris,!appengine
+
+package isatty
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+// IsTerminal returns true if the given file descriptor is a terminal.
+// see: https://src.illumos.org/source/xref/illumos-gate/usr/src/lib/libc/port/gen/isatty.c
+func IsTerminal(fd uintptr) bool {
+	_, err := unix.IoctlGetTermio(int(fd), unix.TCGETA)
+	return err == nil
+}
+
+// IsCygwinTerminal return true if the file descriptor is a cygwin or msys2
+// terminal. This is also always false on this environment.
+func IsCygwinTerminal(fd uintptr) bool {
+	return false
+}
diff --git a/vendor/github.com/mattn/go-isatty/isatty_tcgets.go b/vendor/github.com/mattn/go-isatty/isatty_tcgets.go
new file mode 100644
index 00000000..0337d8cf
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/isatty_tcgets.go
@@ -0,0 +1,20 @@
+//go:build (linux || aix || zos) && !appengine && !tinygo
+// +build linux aix zos
+// +build !appengine
+// +build !tinygo
+
+package isatty
+
+import "golang.org/x/sys/unix"
+
+// IsTerminal return true if the file descriptor is terminal.
+func IsTerminal(fd uintptr) bool {
+	_, err := unix.IoctlGetTermios(int(fd), unix.TCGETS)
+	return err == nil
+}
+
+// IsCygwinTerminal return true if the file descriptor is a cygwin or msys2
+// terminal. This is also always false on this environment.
+func IsCygwinTerminal(fd uintptr) bool {
+	return false
+}
diff --git a/vendor/github.com/mattn/go-isatty/isatty_windows.go b/vendor/github.com/mattn/go-isatty/isatty_windows.go
new file mode 100644
index 00000000..8e3c9917
--- /dev/null
+++ b/vendor/github.com/mattn/go-isatty/isatty_windows.go
@@ -0,0 +1,125 @@
+//go:build windows && !appengine
+// +build windows,!appengine
+
+package isatty
+
+import (
+	"errors"
+	"strings"
+	"syscall"
+	"unicode/utf16"
+	"unsafe"
+)
+
+const (
+	objectNameInfo uintptr = 1
+	fileNameInfo           = 2
+	fileTypePipe           = 3
+)
+
+var (
+	kernel32                         = syscall.NewLazyDLL("kernel32.dll")
+	ntdll                            = syscall.NewLazyDLL("ntdll.dll")
+	procGetConsoleMode               = kernel32.NewProc("GetConsoleMode")
+	procGetFileInformationByHandleEx = kernel32.NewProc("GetFileInformationByHandleEx")
+	procGetFileType                  = kernel32.NewProc("GetFileType")
+	procNtQueryObject                = ntdll.NewProc("NtQueryObject")
+)
+
+func init() {
+	// Check if GetFileInformationByHandleEx is available.
+	if procGetFileInformationByHandleEx.Find() != nil {
+		procGetFileInformationByHandleEx = nil
+	}
+}
+
+// IsTerminal return true if the file descriptor is terminal.
+func IsTerminal(fd uintptr) bool {
+	var st uint32
+	r, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, fd, uintptr(unsafe.Pointer(&st)), 0)
+	return r != 0 && e == 0
+}
+
+// Check pipe name is used for cygwin/msys2 pty.
+// Cygwin/MSYS2 PTY has a name like:
+//   \{cygwin,msys}-XXXXXXXXXXXXXXXX-ptyN-{from,to}-master
+func isCygwinPipeName(name string) bool {
+	token := strings.Split(name, "-")
+	if len(token) < 5 {
+		return false
+	}
+
+	if token[0] != `\msys` &&
+		token[0] != `\cygwin` &&
+		token[0] != `\Device\NamedPipe\msys` &&
+		token[0] != `\Device\NamedPipe\cygwin` {
+		return false
+	}
+
+	if token[1] == "" {
+		return false
+	}
+
+	if !strings.HasPrefix(token[2], "pty") {
+		return false
+	}
+
+	if token[3] != `from` && token[3] != `to` {
+		return false
+	}
+
+	if token[4] != "master" {
+		return false
+	}
+
+	return true
+}
+
+// getFileNameByHandle use the undocomented ntdll NtQueryObject to get file full name from file handler
+// since GetFileInformationByHandleEx is not available under windows Vista and still some old fashion
+// guys are using Windows XP, this is a workaround for those guys, it will also work on system from
+// Windows vista to 10
+// see https://stackoverflow.com/a/18792477 for details
+func getFileNameByHandle(fd uintptr) (string, error) {
+	if procNtQueryObject == nil {
+		return "", errors.New("ntdll.dll: NtQueryObject not supported")
+	}
+
+	var buf [4 + syscall.MAX_PATH]uint16
+	var result int
+	r, _, e := syscall.Syscall6(procNtQueryObject.Addr(), 5,
+		fd, objectNameInfo, uintptr(unsafe.Pointer(&buf)), uintptr(2*len(buf)), uintptr(unsafe.Pointer(&result)), 0)
+	if r != 0 {
+		return "", e
+	}
+	return string(utf16.Decode(buf[4 : 4+buf[0]/2])), nil
+}
+
+// IsCygwinTerminal() return true if the file descriptor is a cygwin or msys2
+// terminal.
+func IsCygwinTerminal(fd uintptr) bool {
+	if procGetFileInformationByHandleEx == nil {
+		name, err := getFileNameByHandle(fd)
+		if err != nil {
+			return false
+		}
+		return isCygwinPipeName(name)
+	}
+
+	// Cygwin/msys's pty is a pipe.
+	ft, _, e := syscall.Syscall(procGetFileType.Addr(), 1, fd, 0, 0)
+	if ft != fileTypePipe || e != 0 {
+		return false
+	}
+
+	var buf [2 + syscall.MAX_PATH]uint16
+	r, _, e := syscall.Syscall6(procGetFileInformationByHandleEx.Addr(),
+		4, fd, fileNameInfo, uintptr(unsafe.Pointer(&buf)),
+		uintptr(len(buf)*2), 0, 0)
+	if r == 0 || e != 0 {
+		return false
+	}
+
+	l := *(*uint32)(unsafe.Pointer(&buf))
+	return isCygwinPipeName(string(utf16.Decode(buf[2 : 2+l/2])))
+}