v0.8.0: dep prune, memtest introspection fix, concurrent uploads, x-api-key

Dependency cleanup (ponytail audit):
- Drop 14 unused dependency declarations across 7 crates; quick-xml and
  x509-parser leave the tree entirely (SAML cert/XML work is handled by
  bergshamra + roxmltree).

Fixes:
- introspect: drop the over-broad "microsoft" UTF-16 bulk-scan marker that
  mislabeled Secure-Boot-signed non-Windows bootables (memtest86, signed
  BSDs, firmware tools) as Windows — the string lives in their MS-signed
  EFI loader's FAT long-filename entries. INTROSPECT_REV 3 -> 4 re-probes
  existing local ISOs on startup so the bogus label clears on upgrade.
- upload: begin_upload now reclaims an abandoned <id>.partial instead of
  rejecting the re-upload with "already uploading". Robust against browser
  refresh, tab close, and dropped connections (the chunked protocol can't
  resume a dead session anyway).

Features:
- Storage upload: multi-file + concurrent. Each dropped/selected .iso gets
  its own progress row and uploads independently; a single page-leave guard
  plus a pagehide keepalive-abort replace the old shared singletons.
- Operator API key (x-api-key): a persisted key authenticates /api/* exactly
  like an operator session, for Postman/scripts. New core ApiKeyStore
  (generated on first run, regenerable), accepted in require_auth alongside
  the session cookie, surfaced in Settings -> Advanced with copy + regenerate
  and a usage reference. GET /api/api-key + POST /api/api-key/regenerate.

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

Cargo.toml

@@ -12,7 +12,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.7.5"
+version = "0.8.0"
 edition = "2021"
 rust-version = "1.95"
 license = "MIT OR Apache-2.0"
@@ -82,8 +82,6 @@ lettre = { version = "0.11", default-features = false, features = ["smtp-transpo
 # SP layer (AuthnRequest, metadata parse, SAMLResponse semantics) on top.
 bergshamra = "0.5"
 roxmltree = "0.21"
-quick-xml = "0.40"
-x509-parser = "0.18"
 # flate2 default backend is miniz_oxide (pure Rust) — do NOT enable the
 # zlib/zlib-ng C backends, which would break the musl-static build.
 flate2 = "1.1"