v0.6.2: Mythos Validation — full-codebase polish, hot-path optimizations, dhcproto 0.15

Codebase-wide review pass: finish or remove every loose end, take the
safe performance wins on the serving hot paths, and refresh the
dependency tree for reliability. No behavior changes for working
clients; legacy clients get clearer protocol errors.

Finalize / cleanup:
- Remove mac_allowlist/subnet_allowlist config fields — parsed but never
  enforced since introduction; the operator wants line-of-sight serving,
  so the honest fix is deletion, not wiring.
- Remove dead ClientRegistry API (get, set_selected_target,
  always-None selected_target field, never-emitted DhcpRequest/
  HttpIsoAsset events).
- TFTP: reject WRQ with ERR_ILLEGAL_OP and non-octet modes with a clear
  error instead of silent timeouts (legacy-client friendliness); fold
  plan_window into cfg(test); drop the unused-constant keep-alive hack.
- rustfmt sweep over the six files with accumulated drift.

Hot-path optimizations (all behavior-preserving):
- Serve embedded iPXE binaries zero-copy (Cow over rodata) on both TFTP
  and HTTP — was a ~1 MiB heap copy per boot file request.
- Cache the composited PXE boot-menu background PNG keyed on the
  branding logo revision — was ~50-200 ms of image work per booting
  client; now one compose per logo change.
- Run bcrypt verify/hash on the blocking pool (boot password gate,
  login, setup, credential rotation) so CPU-heavy auth can't stall the
  workers streaming ISO ranges to imaging machines.
- iso_raw: reuse the already-cloned IsoMeta for path resolution instead
  of a second registry lock + deep clone per range request.
- DriverEscalation: amortize the TTL sweep (1-min interval + inline
  staleness check) instead of an O(map) retain per DHCP packet.
- format_mac: one allocation instead of four per datagram.
- Introspection haystack sized to min(scan cap, file size) — was
  guaranteed a 32 MiB realloc on every large-ISO probe.

Robustness:
- parse_range: malformed Range headers are now ignored per RFC 7233
  (200 + full body) instead of answered with a bogus 206.

Dependencies:
- dhcproto 0.12 -> 0.15: drops the deprecated/unmaintained
  trust-dns-proto from the tree (hickory-proto), three releases of DHCP
  option coverage. Compiles + passes the full suite unchanged.
- socket2 0.6 (dedupes tree), bcrypt 0.19, tower-http 0.6.11 (sheds
  iri-string), tokio 1.52.3 / hyper 1.10 lockfile refresh; dead nom
  workspace entry removed; requested versions synced to shipped reality.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Cargo.toml

@@ -12,7 +12,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.6.1"
+version = "0.6.2"
 edition = "2021"
 rust-version = "1.95"
 license = "MIT OR Apache-2.0"
@@ -20,21 +20,23 @@ repository = "https://gitea.milesward.dev/mward4/OpenPXE"
 authors = ["OpenPXE contributors"]
 
 [workspace.dependencies]
-tokio = { version = "1.40", features = ["full"] }
+tokio = { version = "1.52", features = ["full"] }
 tokio-util = { version = "0.7", features = ["io"] }
 tokio-stream = { version = "0.1", features = ["sync"] }
 futures = "0.3"
 async-trait = "0.1"
 
-dhcproto = "0.12"
-socket2 = { version = "0.5", features = ["all"] }
+# v0.6.2: dhcproto 0.15 drops the deprecated trust-dns-proto dependency
+# (replaced by hickory-proto) and carries three releases of DHCP option
+# coverage accumulated upstream — both directly relevant to the proxy core.
+dhcproto = "0.15"
+socket2 = { version = "0.6", features = ["all"] }
 bytes = "1.7"
-nom = "7.1"
 
 axum = { version = "0.7", features = ["macros", "multipart", "http2"] }
 tower = "0.5"
 tower-http = { version = "0.6", features = ["fs", "trace", "cors", "limit"] }
-hyper = "1.4"
+hyper = "1.9"
 reqwest = { version = "0.12", default-features = false, features = ["rustls-tls", "stream", "json"] }
 
 serde = { version = "1.0", features = ["derive"] }
@@ -52,9 +54,11 @@ thiserror = "2.0"
 clap = { version = "4.5", features = ["derive", "env"] }
 uuid = { version = "1.10", features = ["v4", "serde"] }
 time = { version = "0.3", features = ["serde", "serde-human-readable", "formatting", "macros"] }
+# sha2 stays 0.10 deliberately: bergshamra-crypto requires ^0.10, and
+# bumping to 0.11 would split the RustCrypto digest stack in the tree.
 sha2 = "0.10"
 hex = "0.4"
-bcrypt = "0.15"
+bcrypt = "0.19"
 parking_lot = "0.12"
 rust-embed = { version = "8.5", features = ["include-exclude"] }