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/http-api/src/app.rs

@@ -147,6 +147,14 @@ pub fn build_router(state: AppState) -> Router {
         .route("/api/logout", post(auth_api::api_logout))
         .route("/api/me", get(auth_api::api_me))
         .route("/api/me/credentials", put(auth_api::api_update_credentials))
+        // v0.8.0: operator API key surface (read current + regenerate).
+        // Gated by require_auth like the rest of /api/*; a logged-in
+        // operator or an x-api-key holder can read/rotate it.
+        .route("/api/api-key", get(auth_api::api_api_key_get))
+        .route(
+            "/api/api-key/regenerate",
+            post(auth_api::api_api_key_regenerate),
+        )
         // SAML SSO configuration (FleetDM-shaped). Gated behind auth — the
         // operator pastes their IdP metadata, Entity ID, and toggles here.
         .route("/api/sso", get(api_sso_get).put(api_sso_put))
@@ -1944,6 +1952,10 @@ async fn api_docs() -> Json<serde_json::Value> {
                      "summary": "Auth status — { setup_required, authenticated, user }. Always 200."},
                     {"method": "PUT", "path": "/api/me/credentials",
                      "summary": "Rotate the admin's credentials. Body: { current_password, new_username?, new_password? }. Revokes all other sessions on success."},
+                    {"method": "GET", "path": "/api/api-key",
+                     "summary": "Return the operator API key + the header to send it in (x-api-key). That header authenticates API calls without a browser session — full operator access."},
+                    {"method": "POST", "path": "/api/api-key/regenerate",
+                     "summary": "Mint a fresh API key, invalidating the previous one immediately."},
                 ],
             },
             {