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/webui/src/logo.svg

@@ -1,32 +1,25 @@
-<svg viewBox="0 0 200 130" xmlns="http://www.w3.org/2000/svg" fill="none">
-  <title>PXEForge</title>
+<svg viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg">
+  <title>OpenPXE</title>
+  <!-- Brand mark to match openpxe.com: a circular medallion filled with
+       the "rainbow-horizon" gradient, sliding 200% across to give a slow
+       hue rotation. Subtle stroke + drop shadow for legibility on either
+       theme. SMIL keeps it self-driving with no JS or CSS dependency. -->
   <defs>
-    <linearGradient id="anvilBody" x1="0" y1="0" x2="0" y2="1">
-      <stop offset="0%" stop-color="#aab3c2"/>
-      <stop offset="55%" stop-color="#7d8696"/>
-      <stop offset="100%" stop-color="#525a6b"/>
-    </linearGradient>
-    <linearGradient id="anvilFace" x1="0" y1="0" x2="0" y2="1">
-      <stop offset="0%" stop-color="#cdd5e1"/>
-      <stop offset="100%" stop-color="#9aa3b3"/>
-    </linearGradient>
-    <linearGradient id="anvilBase" x1="0" y1="0" x2="0" y2="1">
-      <stop offset="0%" stop-color="#3b4252"/>
-      <stop offset="100%" stop-color="#252a36"/>
+    <linearGradient id="opxRainbow" x1="0" y1="0" x2="1" y2="0">
+      <stop offset="0%"     stop-color="#330f1f"/>
+      <stop offset="12.56%" stop-color="#c83228"/>
+      <stop offset="25.06%" stop-color="#fb8841"/>
+      <stop offset="37.56%" stop-color="#d3dd92"/>
+      <stop offset="50.06%" stop-color="#59824f"/>
+      <stop offset="62.06%" stop-color="#002414"/>
+      <stop offset="74.06%" stop-color="#00143d"/>
+      <stop offset="86.06%" stop-color="#2874d7"/>
+      <stop offset="100%"   stop-color="#99c2ff"/>
+      <animate attributeName="x1" values="0;-1;0" dur="12s" repeatCount="indefinite"/>
+      <animate attributeName="x2" values="1;0;1"  dur="12s" repeatCount="indefinite"/>
     </linearGradient>
   </defs>
-  <!-- Horn (left point) + face (top) -->
-  <path d="M14 36 L72 30 L162 30 L162 46 L72 46 Z"
-        fill="url(#anvilFace)" stroke="#1d2330" stroke-width="2.4" stroke-linejoin="round"/>
-  <!-- Body / waist -->
-  <path d="M70 46 L160 46 L142 70 L88 70 Z"
-        fill="url(#anvilBody)" stroke="#1d2330" stroke-width="2.4" stroke-linejoin="round"/>
-  <!-- Base plinth -->
-  <path d="M62 96 L168 96 L160 110 L70 110 Z"
-        fill="url(#anvilBase)" stroke="#0d1018" stroke-width="2.4" stroke-linejoin="round"/>
-  <!-- Pillar between body and base -->
-  <rect x="92" y="70" width="46" height="26" fill="url(#anvilBody)"
-        stroke="#1d2330" stroke-width="2.4"/>
-  <!-- Highlight along top face -->
-  <line x1="74" y1="34" x2="158" y2="34" stroke="#e6ecf5" stroke-width="1.2" opacity="0.7"/>
+  <!-- Outer hairline ring softens the edge in light mode; subtle in dark. -->
+  <circle cx="12" cy="12" r="10.5" fill="url(#opxRainbow)"
+          stroke="rgba(0,0,0,0.18)" stroke-width="0.6"/>
 </svg>