update dependencies and features for aimdb-core; add heapless and thiserror, and update thiserror version in workspace

Author: lxsaah

Cargo.lock

@@ -4,7 +4,7 @@ members = [
     "aimdb-connectors",
     "aimdb-adapters",
     "tools/aimdb-cli",
-    "examples"
+    "examples",
 ]
 resolver = "2"
 
@@ -27,7 +27,7 @@ tokio = { version = "1.0", features = ["macros", "rt-multi-thread"] }
 serde = { version = "1.0", features = ["derive"] }
 
 # Error handling
-thiserror = "1.0"
+thiserror = "2.0.16"
 
 # Basic observability
 tracing = "0.1"
@@ -43,4 +43,4 @@ tokio-test = "0.4"
 
 [workspace.metadata.docs.rs]
 all-features = true
-rustdoc-args = ["--cfg", "docsrs"]
+rustdoc-args = ["--cfg", "docsrs"]

Cargo.toml

@@ -5,4 +5,14 @@ edition.workspace = true
 license.workspace = true
 description = "Core database engine for AimDB - async in-memory storage with real-time synchronization"
 
+[features]
+default = ["std"]
+std = ["thiserror"]
+
 [dependencies]
+# Error handling - only for std environments
+thiserror = { workspace = true, optional = true }
+
+[dev-dependencies]
+# For no_std testing
+heapless = "0.9.1"