Add native self-hosted instance connection to fluxer_desktop

Trimmed monorepo checkout (fluxer_desktop + packages/voice_engine_v2 +
tools/ci) with a "Connect to a Different Server" menu item and popout
that lets the desktop app switch to any self-hosted Fluxer instance,
plus fixes for well-known discovery on single-domain self-hosted
deployments and a false-positive ERR_ABORTED on same-origin client
redirects during the switch. Defaults to chat.fluxr.chat and uses an
isolated userData directory from the official build.

fluxer_desktop/native/rust/src/platform_info/mod.rs

@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+pub mod probe_helpers;

fluxer_desktop/native/rust/src/platform_info/probe_helpers.rs

@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+pub fn vendor_name(vendor_id: u32) -> Option<&'static str> {
+    match vendor_id {
+        0x1002 | 0x1022 => Some("AMD"),
+        0x106b => Some("Apple"),
+        0x10de => Some("NVIDIA"),
+        0x1234 => Some("QEMU"),
+        0x1414 => Some("Microsoft"),
+        0x15ad => Some("VMware"),
+        0x1af4 => Some("Virtio"),
+        0x1b36 => Some("QEMU"),
+        0x5143 => Some("Qualcomm"),
+        0x8086 => Some("Intel"),
+        _ => None,
+    }
+}
+
+pub fn vendor_id_from_name(name: &str) -> u32 {
+    let lower = name.to_ascii_lowercase();
+    if lower.contains("apple") {
+        return 0x106b;
+    }
+    if lower.contains("amd") || lower.contains("radeon") {
+        return 0x1002;
+    }
+    if lower.contains("intel") {
+        return 0x8086;
+    }
+    if lower.contains("nvidia") {
+        return 0x10de;
+    }
+    if lower.contains("microsoft") {
+        return 0x1414;
+    }
+    0
+}
+
+pub fn write_hex_u64(value: u64) -> String {
+    format!("0x{value:x}")
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ParseHexIdError {
+    InvalidHexId,
+    InvalidDigit,
+}
+
+pub fn parse_hex_id(raw: &str) -> Result<u32, ParseHexIdError> {
+    let mut trimmed = raw.trim();
+    if let Some(rest) = trimmed
+        .strip_prefix("0x")
+        .or_else(|| trimmed.strip_prefix("0X"))
+    {
+        trimmed = rest;
+    }
+    if trimmed.is_empty() || trimmed.len() > 8 {
+        return Err(ParseHexIdError::InvalidHexId);
+    }
+    u32::from_str_radix(trimmed, 16).map_err(|_| ParseHexIdError::InvalidDigit)
+}
+
+pub fn is_drm_card_name(name: &str) -> bool {
+    let Some(rest) = name.strip_prefix("card") else {
+        return false;
+    };
+    !rest.is_empty() && rest.bytes().all(|ch| ch.is_ascii_digit())
+}
+
+pub fn basename(path: &str) -> &str {
+    path.rsplit_once('/').map_or(path, |(_, base)| base)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_hex_id_accepts_sysfs_hex_ids() {
+        assert_eq!(0x8086, parse_hex_id("0x8086\n").unwrap());
+        assert_eq!(0x10de, parse_hex_id("10DE").unwrap());
+        assert_eq!(Err(ParseHexIdError::InvalidHexId), parse_hex_id("0x"));
+    }
+
+    #[test]
+    fn is_drm_card_name_accepts_cards_but_rejects_connectors_render_nodes() {
+        assert!(is_drm_card_name("card0"));
+        assert!(is_drm_card_name("card12"));
+        assert!(!is_drm_card_name("card0-DP-1"));
+        assert!(!is_drm_card_name("renderD128"));
+    }
+
+    #[test]
+    fn vendor_id_helpers() {
+        assert_eq!(0x106b, vendor_id_from_name("Apple M3 GPU"));
+        assert_eq!(Some("NVIDIA"), vendor_name(0x10de));
+        assert_eq!(None, vendor_name(0xffff));
+    }
+}