Renamed the Web package as Infrastructure (#25)

This PR contains the work done to rename the _Web_ package as _Infrastructure_, to provide a clear naming and purpose to this particular package within the project.

To provide further details about the work:

* Infrastructure
  * Asset fingerprinting: an FNV-1a token derived from the static files directory, appended as ?v= to asset URLs so deploys bust caches; pre-rendered pages also revalidate via weak ETags.
  * New middlewares: fixed-window RateLimitMiddleware (per-client budgets keyed by trusted X-Forwarded-For or remote address) and VaryMiddleware (Accept-Encoding on every response); SecurityHeadersMiddleware now also stamps error responses.
  * Auto-generated HEAD endpoints, cache max-age configuration, and Docker build/Compose refinements.
  * Protocols and scaffolding: Asset/AssetExtension, the Page protocol (viewport, stylesheets, scripts, versioned URLs), and LocalizedRequestContext.
  * Rate limiter's counter store swapped from an actor to a Mutex (no executor hop per request) with amortized batch eviction instead of O(n²) scans under client floods.
  * FingerprintAssets reports unreadable files to a logger instead of silently producing a token that never busts their cache.

Reviewed-on: rock-n-code/loud-amsterdam#25
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Services/Website/Sources/Library/Public/Extensions/AbsoluteConfigKey+Constants.swift

@@ -3,7 +3,9 @@ import Configuration
 extension AbsoluteConfigKey {
     /// A namespace for the static files cache configuration keys, as absolute keys.
     public enum Cache {
-        /// The absolute configuration key for the max-age, in seconds, applied to text-based static files.
+        /// The absolute configuration key for the max-age, in seconds, applied to fingerprinted assets and fonts.
+        public static let maxAgeAsset: AbsoluteConfigKey = .init(.Cache.maxAgeAsset)
+        /// The absolute configuration key for the max-age, in seconds, applied to unversioned text-based static files.
         public static let maxAgeText: AbsoluteConfigKey = .init(.Cache.maxAgeText)
         /// The absolute configuration key for the max-age, in seconds, applied to image static files.
         public static let maxAgeImage: AbsoluteConfigKey = .init(.Cache.maxAgeImage)
@@ -50,6 +52,15 @@ extension AbsoluteConfigKey {
         /// The absolute configuration key for the minimum log level.
         public static let level: AbsoluteConfigKey = .init(.Log.level)
     }
+    /// A namespace for the rate limit configuration keys, as absolute keys.
+    public enum RateLimit {
+        /// The absolute configuration key for the number of requests admitted per client per window.
+        public static let limit: AbsoluteConfigKey = .init(.RateLimit.limit)
+        /// The absolute configuration key for the window length, in seconds.
+        public static let window: AbsoluteConfigKey = .init(.RateLimit.window)
+        /// The absolute configuration key for keying clients by the first `X-Forwarded-For` entry.
+        public static let trustForwardedFor: AbsoluteConfigKey = .init(.RateLimit.trustForwardedFor)
+    }
     /// A namespace for the path configuration keys, as absolute keys.
     public enum Path {
         /// The absolute configuration key for the directory the static files are served from.