fix: remediate severity-ordered review findings across cache, scanners, and proxies

- H2: gormstore soft-delete + storage_key UNIQUE collision; re-save after eviction succeeds
- H1: cache getOrFetch cache-hit branch no longer runs CheckVulnerabilities on metadata entries
- M2: cache store() streams upstream body to temp file + SHA256 instead of double-buffering
- H3/L3: FetchResult/FetchFunc plumbing (+RequiresAuth/AuthProvider); proxy closures adapted;
        goproxy strips git+ prefix from UpstreamURL
- H4: scanner normalizes bypass package names; CheckVulnerabilities builds normalized packageKey
- M4: requireAdmin routes through extractAPIKey -> ValidateAPIKey -> admin role check
- M5: network client keeps only final RecordFailure (one count per attempt cycle)
- M3: normalizeOriginHost + buildCheckOrigin rewrite; origin_test.go added
- M1: app lifecycle cancel func; Run -> Shutdown on listen error (sole cache owner); JoinHostPort
- M6: VulnerabilityThresholds defaults all -1 so BlockOnSeverity governs
- L4: metadata.NormalizeSeverity at 4 severity-count sites (MEDIUM->MODERATE consistency)
- L1: handleDeleteBypass uses structured *errors.Error + ErrCodeNotFound
- L2: pypi extractVersionFromFilename (wheel/2nd segment, non-wheel/last digit segment);
      cacheVersion uses full unique basename; regression tests added
- L5: document per-instance ValidationCache key scoping; rename packageURL param to resource

All: go build ./... && go vet ./... && go test ./... pass; golangci-lint clean.

pkg/app/handlers_vulnerabilities.go

@@ -77,11 +77,19 @@ func (a *App) handleVulnerabilities(c *fiber.Ctx) error {
 		bypasses = []*metadata.CVEBypass{}
 	}
 
-	// Build bypass map for fast lookup
+	// Build bypass map for fast lookup.
+	// Normalize Go cache-key names (modulePath/@v/version.zip) to the
+	// natural module path so admin bypass targets like
+	// "go/github.com/foo/[email protected]" match the package.
+	bypassName := name
+	if registry == "go" {
+		if idx := strings.Index(bypassName, "/@v/"); idx >= 0 {
+			bypassName = bypassName[:idx]
+		}
+	}
+	packageKey := registry + "/" + bypassName + "@" + version
+	packageKeyNoVersion := registry + "/" + bypassName
 	bypassedCVEs := make(map[string]*metadata.CVEBypass)
-	packageKey := registry + "/" + name + "@" + version
-	packageKeyNoVersion := registry + "/" + name
-
 	for _, bypass := range bypasses {
 		if bypass.Type == metadata.BypassTypeCVE && bypass.Active {
 			// Check if bypass applies to this package
@@ -110,7 +118,7 @@ func (a *App) handleVulnerabilities(c *fiber.Ctx) error {
 			}
 		} else {
 			// Count non-bypassed vulnerabilities by severity
-			severityCounts[strings.ToUpper(vuln.Severity)]++
+			severityCounts[metadata.NormalizeSeverity(vuln.Severity)]++
 		}
 
 		enrichedVuln := map[string]interface{}{