Add direct PowerShell execution regions

IMPLEMENTATION_PLAN.md

@@ -380,8 +380,15 @@ priorities.
       unproved identities, and unknown receivers retain unknown/incomplete
       facts. Module-qualified identities are catalogued, but the parser keeps
       rejecting those forms atomically until the region-emission slice can
-      expose every body command. Continue in small slices with direct `&` / `.` and synchronous
-      current-runspace callbacks; child process/runspace jobs and parallel
+      expose every body command. The first direct-operator sub-slice now handles
+      currently supported command interiors in typed synchronous `& {}` and
+      `. {}` regions without synthetic host commands. It isolates ordinary
+      direct-call binding and command-resolution exit mutation, invalidates
+      explicitly escaping scope/provider mutation, carries shared location
+      outcomes, and keeps block arguments and leading `param()` declarations
+      atomic. Ordinary assignment state transfer remains an atomic task 7.5b
+      follow-up; task 7.5b is not complete. Continue with synchronous current-runspace callbacks;
+      child process/runspace jobs and parallel
       blocks; deferred breakpoint/event/completion actions; then unknown
       receiver and nested/adversarial matrices. Preserve script blocks proved
       to be data as opaque values, expose ambiguous bodies with incomplete

src/ShellSyntaxTree/Internal/Pwsh/Parsing/PwshCommandParser.cs

@@ -206,8 +206,14 @@ private static bool TryDetectUnsupportedInvocationShape(
                     index + 1 < tokens.Count &&
                     tokens[index + 1].Kind == PwshTokenKind.ScriptBlock)
                 {
-                    reason = "call-operator script blocks are not supported in v0.3";
-                    return true;
+                    if (!verbSlot)
+                    {
+                        reason = "a call-operator script block is only supported at command position";
+                        return true;
+                    }
+
+                    verbSlot = false;
+                    continue;
                 }
 
                 verbSlot = token.OperatorText is "&&" or "||" or ";" or "|" or "(" or "&";
@@ -218,8 +224,12 @@ private static bool TryDetectUnsupportedInvocationShape(
             {
                 if (token.Value == ".")
                 {
-                    reason = "the dot-source invocation operator is not supported in v0.2";
-                    return true;
+                    if (index + 1 >= tokens.Count ||
+                        tokens[index + 1].Kind != PwshTokenKind.ScriptBlock)
+                    {
+                        reason = "the dot-source invocation operator is not supported in v0.2";
+                        return true;
+                    }
                 }
 
                 if (IsUnsupportedModuleQualifiedCmdlet(token.Value))