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.

1 files changed, 0 insertions, 160 deletions

diff --git a/vendor/httpdate/src/lib.rs b/vendor/httpdate/src/lib.rs
deleted file mode 100644
index 88cb6fa7..00000000
--- a/vendor/httpdate/src/lib.rs
+++ /dev/null
@@ -1,160 +0,0 @@
-//! Date and time utils for HTTP.
-//!
-//! Multiple HTTP header fields store timestamps.
-//! For example a response created on May 15, 2015 may contain the header
-//! `Date: Fri, 15 May 2015 15:34:21 GMT`. Since the timestamp does not
-//! contain any timezone or leap second information it is equvivalent to
-//! writing 1431696861 Unix time. Rust’s `SystemTime` is used to store
-//! these timestamps.
-//!
-//! This crate provides two public functions:
-//!
-//! * `parse_http_date` to parse a HTTP datetime string to a system time
-//! * `fmt_http_date` to format a system time to a IMF-fixdate
-//!
-//! In addition it exposes the `HttpDate` type that can be used to parse
-//! and format timestamps. Convert a sytem time to `HttpDate` and vice versa.
-//! The `HttpDate` (8 bytes) is smaller than `SystemTime` (16 bytes) and
-//! using the display impl avoids a temporary allocation.
-#![forbid(unsafe_code)]
-
-use std::error;
-use std::fmt::{self, Display, Formatter};
-use std::io;
-use std::time::SystemTime;
-
-pub use date::HttpDate;
-
-mod date;
-
-/// An opaque error type for all parsing errors.
-#[derive(Debug)]
-pub struct Error(());
-
-impl error::Error for Error {}
-
-impl Display for Error {
-    fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
-        f.write_str("string contains no or an invalid date")
-    }
-}
-
-impl From<Error> for io::Error {
-    fn from(e: Error) -> io::Error {
-        io::Error::new(io::ErrorKind::Other, e)
-    }
-}
-
-/// Parse a date from an HTTP header field.
-///
-/// Supports the preferred IMF-fixdate and the legacy RFC 805 and
-/// ascdate formats. Two digit years are mapped to dates between
-/// 1970 and 2069.
-pub fn parse_http_date(s: &str) -> Result<SystemTime, Error> {
-    s.parse::<HttpDate>().map(|d| d.into())
-}
-
-/// Format a date to be used in a HTTP header field.
-///
-/// Dates are formatted as IMF-fixdate: `Fri, 15 May 2015 15:34:21 GMT`.
-pub fn fmt_http_date(d: SystemTime) -> String {
-    format!("{}", HttpDate::from(d))
-}
-
-#[cfg(test)]
-mod tests {
-    use std::str;
-    use std::time::{Duration, UNIX_EPOCH};
-
-    use super::{fmt_http_date, parse_http_date, HttpDate};
-
-    #[test]
-    fn test_rfc_example() {
-        let d = UNIX_EPOCH + Duration::from_secs(784111777);
-        assert_eq!(
-            d,
-            parse_http_date("Sun, 06 Nov 1994 08:49:37 GMT").expect("#1")
-        );
-        assert_eq!(
-            d,
-            parse_http_date("Sunday, 06-Nov-94 08:49:37 GMT").expect("#2")
-        );
-        assert_eq!(d, parse_http_date("Sun Nov  6 08:49:37 1994").expect("#3"));
-    }
-
-    #[test]
-    fn test2() {
-        let d = UNIX_EPOCH + Duration::from_secs(1475419451);
-        assert_eq!(
-            d,
-            parse_http_date("Sun, 02 Oct 2016 14:44:11 GMT").expect("#1")
-        );
-        assert!(parse_http_date("Sun Nov 10 08:00:00 1000").is_err());
-        assert!(parse_http_date("Sun Nov 10 08*00:00 2000").is_err());
-        assert!(parse_http_date("Sunday, 06-Nov-94 08+49:37 GMT").is_err());
-    }
-
-    #[test]
-    fn test3() {
-        let mut d = UNIX_EPOCH;
-        assert_eq!(d, parse_http_date("Thu, 01 Jan 1970 00:00:00 GMT").unwrap());
-        d += Duration::from_secs(3600);
-        assert_eq!(d, parse_http_date("Thu, 01 Jan 1970 01:00:00 GMT").unwrap());
-        d += Duration::from_secs(86400);
-        assert_eq!(d, parse_http_date("Fri, 02 Jan 1970 01:00:00 GMT").unwrap());
-        d += Duration::from_secs(2592000);
-        assert_eq!(d, parse_http_date("Sun, 01 Feb 1970 01:00:00 GMT").unwrap());
-        d += Duration::from_secs(2592000);
-        assert_eq!(d, parse_http_date("Tue, 03 Mar 1970 01:00:00 GMT").unwrap());
-        d += Duration::from_secs(31536005);
-        assert_eq!(d, parse_http_date("Wed, 03 Mar 1971 01:00:05 GMT").unwrap());
-        d += Duration::from_secs(15552000);
-        assert_eq!(d, parse_http_date("Mon, 30 Aug 1971 01:00:05 GMT").unwrap());
-        d += Duration::from_secs(6048000);
-        assert_eq!(d, parse_http_date("Mon, 08 Nov 1971 01:00:05 GMT").unwrap());
-        d += Duration::from_secs(864000000);
-        assert_eq!(d, parse_http_date("Fri, 26 Mar 1999 01:00:05 GMT").unwrap());
-    }
-
-    #[test]
-    fn test_fmt() {
-        let d = UNIX_EPOCH;
-        assert_eq!(fmt_http_date(d), "Thu, 01 Jan 1970 00:00:00 GMT");
-        let d = UNIX_EPOCH + Duration::from_secs(1475419451);
-        assert_eq!(fmt_http_date(d), "Sun, 02 Oct 2016 14:44:11 GMT");
-    }
-
-    #[allow(dead_code)]
-    fn testcase(data: &[u8]) {
-        if let Ok(s) = str::from_utf8(data) {
-            println!("{:?}", s);
-            if let Ok(d) = parse_http_date(s) {
-                let o = fmt_http_date(d);
-                assert!(!o.is_empty());
-            }
-        }
-    }
-
-    #[test]
-    fn size_of() {
-        assert_eq!(::std::mem::size_of::<HttpDate>(), 8);
-    }
-
-    #[test]
-    fn test_date_comparison() {
-        let a = UNIX_EPOCH + Duration::from_secs(784111777);
-        let b = a + Duration::from_secs(30);
-        assert!(a < b);
-        let a_date: HttpDate = a.into();
-        let b_date: HttpDate = b.into();
-        assert!(a_date < b_date);
-        assert_eq!(a_date.cmp(&b_date), ::std::cmp::Ordering::Less)
-    }
-
-    #[test]
-    fn test_parse_bad_date() {
-        // 1994-11-07 is actually a Monday
-        let parsed = "Sun, 07 Nov 1994 08:48:37 GMT".parse::<HttpDate>();
-        assert!(parsed.is_err())
-    }
-}