v0.4.0: upload telemetry, host log, jet-black UI

- Upload reliability + diagnostics:
  - api_upload_iso now distinguishes clean EOF from mid-stream errors;
    a truncated multipart body (proxy buffer cap, network drop) returns
    400 with the cause and a "try the LAN IP" hint instead of silently
    finalising a partial file.
  - Per-stage tracing (begin/MB-watermark/finish/abort) so a stuck
    upload is debuggable from the Terminal tab.
  - Web upload UI surfaces bytes/total, percent, throughput, ETA, and
    maps 413/502/504/network-drop to actionable hints.
- New BootLog feature under Hosts:
  - openpxe-core::BootLog — bounded in-memory ring (500) + append-only
    JSONL on disk, recording (timestamp, mac, ip, target_id,
    target_title) every time a boot entry script is served.
  - iPXE per-entry chain URLs grow ?mac=${mac}; password prompt
    submission carries it through; host-binding short-circuit uses the
    bound MAC. ConnectInfo<SocketAddr> wired for peer IP capture (with
    optional fallback so tower::oneshot in tests still works).
  - GET /api/boot-log endpoint + Host log table under the Hosts tab.
- UI changes:
  - Queue card header "Forge" → "Status".
  - Removed Tinkerbell attribution sentence from Hosts tab.
  - Topbar readiness chip moved into the sidebar footer as
    "Service status: Ready / Advertised to clients / <url>", grouping
    advertised PXE URL with operator-relevant status.
  - Jet-black dark palette (#000 / #0a0a0a / #141414 / #1c1c1c)
    replacing the blue-tinted ramp; terminal toolbar/input recoloured
    to match.
- 89 tests passing (was 85 in v0.3.2); cargo clippy --workspace
  --all-targets clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

crates/http-api/src/state.rs

@@ -1,4 +1,6 @@
-use openpxe_core::{ClientRegistry, DeploymentQueue, HostBindings, LogBus, Metrics, SettingsStore};
+use openpxe_core::{
+    BootLog, ClientRegistry, DeploymentQueue, HostBindings, LogBus, Metrics, SettingsStore,
+};
 use openpxe_iso_store::{IsoStore, NfsManager, SmbManager};
 use std::sync::Arc;
 use time::OffsetDateTime;
@@ -13,6 +15,10 @@ pub struct AppState {
     /// these MACs requests `/boot.ipxe`, we chain straight to the
     /// configured target instead of rendering the menu.
     pub hosts: HostBindings,
+    /// Persistent boot-event log surfaced under the Hosts tab. Records
+    /// every `/boot/<entry>.ipxe` chain that goes on to serve a script
+    /// (i.e. an image actually starting to install on a machine).
+    pub boot_log: BootLog,
     /// Lock-free metrics counters surfaced at `/metrics` in Prometheus
     /// text format. Cheap to clone (handles to atomics).
     pub metrics: Metrics,