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]>

crates/core/Cargo.toml

@@ -27,13 +27,11 @@ tokio = { workspace = true, features = ["sync", "rt", "macros", "time"] }
 bcrypt.workspace = true
 
 # v0.5.1: pure-Rust SAML 2.0 SP. bergshamra = XML-DSig verify + exclusive
-# c14n (no OpenSSL/C). roxmltree/quick-xml parse + build SAML XML;
-# x509-parser pulls the IdP signing cert out of metadata; flate2+base64
-# encode the HTTP-Redirect binding's SAMLRequest.
+# c14n (no OpenSSL/C), plus IdP signing-cert extraction from metadata.
+# roxmltree parses the SAML/metadata XML; flate2+base64 encode the
+# HTTP-Redirect binding's SAMLRequest.
 bergshamra.workspace = true
 roxmltree.workspace = true
-quick-xml.workspace = true
-x509-parser.workspace = true
 flate2.workspace = true
 base64.workspace = true