docs: link tutorials and concepts from the new-module READMEs

Author: tgiachi

src/SquidStd.Actors/README.md

@@ -79,6 +79,11 @@ using var sub = session.SubscribeToEventBus(eventBus, (UserJoinedEvent e) => new
 
 `DisposeAsync` completes the mailbox, drains in-flight work, and faults any still-pending requests.
 
+## Related
+
+- Tutorial: [Actors](https://tgiachi.github.io/squid-std/tutorials/actors.html)
+- Concept: [Messaging models](https://tgiachi.github.io/squid-std/articles/concepts/messaging-models.html)
+
 ## License
 
 MIT — part of [SquidStd](https://github.com/tgiachi/squid-std).

src/SquidStd.Crypto/README.md

@@ -122,6 +122,10 @@ var folderVault = new CryptoFileSystem(new PhysicalFileSystem("/secure/dir"));
 - A wrong passphrase fails the index authentication tag → `CryptographicException`; operations on a locked
   vault throw `InvalidOperationException`.
 
+## Related
+
+- Tutorial: [Crypto (PGP)](https://tgiachi.github.io/squid-std/tutorials/crypto.html)
+
 ## License
 
 MIT — part of [SquidStd](https://github.com/tgiachi/squid-std).

src/SquidStd.Persistence/README.md

@@ -66,6 +66,10 @@ container.ApplyPersistedEntityRegistrations();   // builds descriptors into IPer
 | `SnapshotService`                     | Atomic per-type binary snapshot files with payload checksum.  |
 | `RegisterPersistedEntity<T,TKey>()`   | DI helper recording an entity for descriptor construction.    |
 
+## Related
+
+- Tutorial: [Persistence](https://tgiachi.github.io/squid-std/tutorials/persistence.html)
+
 ## License
 
 MIT — part of [SquidStd](https://github.com/tgiachi/squid-std).

src/SquidStd.Secrets.Aws/README.md

@@ -68,6 +68,10 @@ await foreach (var name in store.ListNamesAsync("db/")) { /* ... */ }
 - **Tested against LocalStack** — the KMS and Secrets Manager adapters are covered by integration tests
   running on a `localstack/localstack` container.
 
+## Related
+
+- Tutorial: [Secrets (KMS / Secrets Manager)](https://tgiachi.github.io/squid-std/tutorials/secrets.html)
+
 ## License
 
 MIT — part of [SquidStd](https://github.com/tgiachi/squid-std).

src/SquidStd.Vfs.Abstractions/README.md

@@ -17,6 +17,10 @@ dotnet add package SquidStd.Vfs.Abstractions
 | `VfsPath` | Static helper that normalizes logical paths to forward-slash, root-relative form and rejects `.`/`..` traversal segments. |
 | `VfsEntry` | Record describing a listed entry: its logical path, byte size and last-modified UTC timestamp. |
 
+## Related
+
+- Tutorial: [Virtual filesystem](https://tgiachi.github.io/squid-std/tutorials/vfs.html)
+
 ## License
 
 MIT — part of [SquidStd](https://github.com/tgiachi/squid-std).

src/SquidStd.Vfs/README.md

@@ -60,6 +60,10 @@ Logical paths are normalized (forward slashes, root-relative) and reject `..` tr
 | `VfsDirectories` | Named directory layout (`DirectoriesConfig` analogue) over any backend. |
 | `RegisterVfsExtensions` | `RegisterVfs(...)` registration. |
 
+## Related
+
+- Tutorial: [Virtual filesystem](https://tgiachi.github.io/squid-std/tutorials/vfs.html)
+
 ## License
 
 MIT — part of [SquidStd](https://github.com/tgiachi/squid-std).