v0.3.0 — rebrand: PXEForge → OpenPXE, Gated → Queued Deployment

Full rename to match the openpxe.com brand. The product now reads as a
polished open-source project rather than a personal-tool nickname:
the anvil/forge metaphor is gone, replaced with the rainbow-horizon
brand mark from the marketing site.

## Naming changes

**PXEForge → OpenPXE** everywhere it's user-visible or developer-
facing:
- All 8 crate package names (`pxeforge-*` → `openpxe-*`).
- The bin crate dir + binary (`crates/pxeforge` → `crates/openpxe`,
  `bin = "openpxe"`).
- Env vars: `PXEFORGE_*` → `OPENPXE_*` (no compat shim — pre-beta).
- Tracing targets: `pxeforge::*` → `openpxe::*`.
- Prometheus metrics: `pxeforge_*` → `openpxe_*` (pre-beta; nobody
  has dashboards on these yet).
- Container image: `gitea.milesward.dev/mward4/openpxe:0.3.0`.
- All in-tree paths: `/var/lib/openpxe/{isos,work,smb}`,
  `/usr/share/openpxe/ipxe`, `/etc/openpxe/...`.
- Unraid template renamed `pxeforge.xml` → `openpxe.xml`.
- README, NEXT_PHASE.md, architecture.md, comments, and the WebUI
  brand string.

**Gated Deployment → Queued Deployment** as the user-facing concept:
- `Settings::TimeoutAction::GatedDeployment` →
  `QueuedDeployment` (with `#[serde(alias = "gated_deployment")]`
  so v0.2.0 settings.json files keep deserializing).
- Rust types: `Gate` → `QueueEntry`, `GateQueue` → `DeploymentQueue`,
  `GateInner` → `QueueEntryInner`.
- File: `crates/core/src/gate.rs` → `crates/core/src/queue.rs`.
- HTTP routes: `/api/gate/*` → `/api/queue/*`. The JSON list key
  flipped from `"gates"` to `"entries"` to match.
- iPXE shortcut: `/boot/_gate.ipxe` → `/boot/_queue.ipxe`. The
  top-level menu's item id is now `queue` instead of `gate`.
- WebUI sidebar tab: "Forge Gate" → "Queue".
- Field on `AppState`: `gates` → `queue`.

## Brand assets

The anvil + forging-sparks logos are dropped:
- `logo.svg` is now a 24×24 medallion filled with the
  `rainbow-horizon` gradient from openpxe.com (sliding hue rotation
  via SMIL on the gradient stops, no JS needed).
- `anvil-forge.svg` renamed to `loader.svg` and rebuilt as a 64×64
  louder version of the same disc — used for page-load transitions
  and the imaging-progress widget. Adds a subtle scale pulse and a
  white inner-glow so it has dimensionality on either theme.

## CSS rename

- `.forge-progress` → `.queue-progress`
- `.forge-progress .anvil` → `.queue-progress .mark`
- `@keyframes forge-sheen` → `queue-sheen`
- `.loader .anvil` → `.loader .mark`
- "Heating the forge…" loader text → "Loading…"

The rest of the layout is untouched. Light/dark theme tokens and the
sidebar/topbar structure carry over from v0.2.0 unchanged — the
brief was "keeping the UI similar."

## Validation

- `cargo build --workspace` — clean.
- `cargo clippy --workspace --all-targets` — no warnings.
- `cargo test --workspace` — **66 tests passing**, same as v0.2.0.
- Local smoke run against the rebuilt release binary verifies:
  - `/boot.ipxe` emits `Queued Deployment` + `item queue` + chains
    `/boot/_queue.ipxe`
  - `/api/queue` returns `{count, entries}`
  - `/metrics` emits `openpxe_queue_count` (renamed)
  - `/assets/logo.svg` and `/assets/loader.svg` serve the new
    rainbow brand SVGs
  - `/api/status` reports version `0.3.0`

## Migration notes for operators on v0.2.0

- Container image path changed: pull
  `gitea.milesward.dev/mward4/openpxe:0.3.0` (not `pxeforge:`).
- Bind mounts: `/var/lib/openpxe/{isos,work,smb}` (not `pxeforge`).
  Move the host path or update the template.
- Env vars: replace `PXEFORGE_*` with `OPENPXE_*`. The Unraid
  template at `deploy/unraid/openpxe.xml` is already updated.
- `settings.json` carries over transparently — the
  `gated_deployment` value is accepted as an alias.
- HTTP API: any external scripts that hit `/api/gate/*` need to
  switch to `/api/queue/*`. The JSON envelope key is `entries`
  instead of `gates`.

crates/core/src/settings.rs

@@ -47,13 +47,13 @@ pub struct Settings {
     /// `timeout_action = LocalHdd`).
     pub default_local_hdd: bool,
 
-    /// When a client hits the Gated Deployment item, how long (seconds) to
+    /// When a client hits the Queued Deployment item, how long (seconds) to
     /// hold it at the gate before giving up and falling back to the menu.
     /// 0 = forever.
     pub gate_wait_max_secs: u32,
 
     /// Optional DNS server advertised on the Network tab. Purely
-    /// informational today — PXEForge does not run a DNS server, but
+    /// informational today — OpenPXE does not run a DNS server, but
     /// operators expect to be able to record what the upstream DNS is.
     /// Empty string = unset (UI shows placeholder).
     pub dns_server: String,
@@ -66,16 +66,20 @@ pub enum TimeoutAction {
     Stay,
     /// Chain the "Boot from Local HDD" entry.
     LocalHdd,
-    /// Put the client into the gate queue, waiting for operator assignment.
+    /// Put the client into the deployment queue, waiting for operator
+    /// assignment. The serde alias keeps v0.2.0 settings.json files
+    /// readable after the v0.3.0 rename — old `"gated_deployment"`
+    /// values deserialize transparently.
     #[default]
-    GatedDeployment,
+    #[serde(alias = "gated_deployment")]
+    QueuedDeployment,
 }
 
 impl Default for Settings {
     fn default() -> Self {
         Self {
             boot_menu_timeout_secs: 600,
-            timeout_action: TimeoutAction::GatedDeployment,
+            timeout_action: TimeoutAction::QueuedDeployment,
             windows_enabled: false,
             smb_host_override: String::new(),
             extra_kernel_args: String::new(),
@@ -103,7 +107,7 @@ impl SettingsStore {
                 Ok(s) => s,
                 Err(e) => {
                     tracing::warn!(
-                        target: "pxeforge::settings",
+                        target: "openpxe::settings",
                         "settings.json present but unreadable ({e}); falling back to defaults"
                     );
                     Settings::default()
@@ -130,7 +134,7 @@ impl SettingsStore {
         }
         let snap = self.snapshot();
         if let Err(e) = self.persist(&snap) {
-            tracing::warn!(target: "pxeforge::settings", "failed to persist settings: {e}");
+            tracing::warn!(target: "openpxe::settings", "failed to persist settings: {e}");
         }
     }
 
@@ -157,7 +161,7 @@ mod tests {
         let store = SettingsStore::load_or_default(dir.path());
         let s = store.snapshot();
         assert_eq!(s.boot_menu_timeout_secs, 600);
-        assert_eq!(s.timeout_action, TimeoutAction::GatedDeployment);
+        assert_eq!(s.timeout_action, TimeoutAction::QueuedDeployment);
         assert!(!s.windows_enabled);
     }