Add structured coroutines and explicit error handling

tools/vscode-gotlin/snippets/gotlin.code-snippets

@@ -52,19 +52,6 @@
     "body": ["@embed(\"${1:path/to/file}\") val ${2:name}: ${3:ByteSlice}"],
     "description": "Embed a file as a top-level value"
   },
-  "Worker": {
-    "prefix": "worker",
-    "body": [
-      "worker ${1:Name} {",
-      "    var ${2:state}: ${3:Int} = ${4:0}",
-      "",
-      "    fun ${5:run}() {",
-      "        $0",
-      "    }",
-      "}"
-    ],
-    "description": "Stateful Gotlin worker"
-  },
   "Rust-style Enum": {
     "prefix": "enum",
     "body": [
@@ -98,14 +85,50 @@
     "body": ["val ${1:target} = ${2:source}.mapTo<${3:Target}>()"],
     "description": "Recursively map compatible classes or enums"
   },
-  "Go Block": {
-    "prefix": "go",
+  "Nullable Safe Access": {
+    "prefix": "safe",
+    "body": ["${1:value}?.${2:field}"],
+    "description": "Safely access a nullable value"
+  },
+  "Non-null Assertion": {
+    "prefix": "nonnull",
+    "body": ["${1:value}!!"],
+    "description": "Assert that a nullable value is non-null"
+  },
+  "Result Function": {
+    "prefix": "resultfun",
     "body": [
-      "go {",
-      "    $0",
+      "fun ${1:name}(${2}): Result<${3:Value}, Error> {",
+      "    val ${4:value} = ${5:operation}()?",
+      "    return Result::Ok(${4:value})",
       "}"
     ],
-    "description": "Run a block concurrently"
+    "description": "Function with Rust-style Result propagation"
+  },
+  "Result Match": {
+    "prefix": "resultmatch",
+    "body": [
+      "match (${1:result}) {",
+      "    Result::Ok(${2:value}) -> { $3 }",
+      "    Result::Err(${4:error}) -> { $0 }",
+      "}"
+    ],
+    "description": "Match a Result value"
+  },
+  "Coroutine Scope": {
+    "prefix": "coroutinescope",
+    "body": ["coroutineScope {", "    $0", "}"],
+    "description": "Structured child coroutine scope"
+  },
+  "Launch Coroutine": {
+    "prefix": "launch",
+    "body": ["launch {", "    $0", "}"],
+    "description": "Launch a structured child coroutine"
+  },
+  "Async Coroutine": {
+    "prefix": "async",
+    "body": ["val ${1:result} = async<${2:Type}> {", "    $0", "}"],
+    "description": "Start a typed deferred coroutine"
   },
   "Defer Call": {
     "prefix": "defer",
@@ -124,7 +147,7 @@
   "Typed SQL Fetch": {
     "prefix": "sqlfetch",
     "body": [
-      "val ${1:rows}: List<*${2:Row}> = sql.from<${2:Row}>()",
+      "val ${1:rows}: List<${2:Row}> = sql.from<${2:Row}>()",
       "    .where { ${3:it.id == id} }",
       "    .fetch(${4:pool}, ${5:ctx})"
     ],
@@ -133,7 +156,7 @@
   "Typed SQL Single": {
     "prefix": "sqlsingle",
     "body": [
-      "val ${1:row}: *${2:Row} = sql.from<${2:Row}>()",
+      "val ${1:row}: ${2:Row} = sql.from<${2:Row}>()",
       "    .where { ${3:it.id == id} }",
       "    .single(${4:pool}, ${5:ctx})"
     ],