fix(speckl): dispatch 'state as <Name>' to parseStateBlockMultiline (cycle 63)

End-to-end compile of FederatedMeetup.speckdl with the new
'state as StateSnapshot' header (cycle 63) surfaced that the
parser's main loop and parseMemberBlock dispatcher were both
missing 'state as ' as a recognized block-starter prefix. The
state-block parser (parseStateBlockMultiline) already extracts
the 'as' clause correctly (cycle 59), but the call site never
reached it: the block fell through the 'state:' / 'state {'
checks and was parsed as a regular member line, producing no
StateNode at all.

Fix: add 'state as ' to the blockStarters list in the main
parse loop, and add a parallel dispatch in parseMemberBlock
that routes 'state as ' headers to parseStateBlockMultiline.
The dispatcher change is symmetric with the existing 'state:'
and 'state {' forms.

Tests: 1 new parser test confirms the dispatch works for
'state as StateSnapshot { ... }'. All 55 tests pass (54
baseline + 1 new). tsc build clean.

End-to-end verified: running generateProtobuf against the
federated-meetup speck with 'state as StateSnapshot' now
emits 'message StateSnapshot { ... }' (correct), where
pre-fix the StateNode was lost entirely.

compiler/__tests__/parser.test.ts

@@ -833,4 +833,24 @@ speck Second {
       }
     });
   });
+
+  // Cycle 63: 'state as <Name> { ... }' must dispatch through the
+  // same parseStateBlockMultiline path as 'state: { ... }'. Cycle 59
+  // added the parser-side extraction of the `as` clause; this test
+  // confirms the block-dispatcher also routes the new header form.
+  describe('state as <Name> dispatch (cycle 63)', () => {
+    it('should dispatch state as StateSnapshot to parseStateBlockMultiline', () => {
+      const content = `speck FederatedMeetup {
+  state as StateSnapshot {
+    branch_id: Nat
+  }
+}`;
+      const ast = parseSpeckContent(content);
+      const state = ast.specks[0].members.find(m => m.type === 'state');
+      if (state?.type === 'state') {
+        expect(state.messageName).toBe('StateSnapshot');
+        expect(state.variables.map(v => v.name)).toEqual(['branch_id']);
+      }
+    });
+  });
 });

compiler/src/parser.ts

@@ -373,7 +373,8 @@ function parseSpeck(lines: string[], startIndex: number): SpeckNode | null {
 
     // Check for block-opening members (those that open braces on the same line)
     const blockStarters = ['state:', 'init:', 'action ', 'event ', 'provenance ', 'bom ', 'interface ',
-      'state {', 'init {', 'verify ', 'constraint ', 'input:', 'output:', 'service ', 'oneof ', 'transition '];
+      'state {', 'init {', 'verify ', 'constraint ', 'input:', 'output:', 'service ', 'oneof ', 'transition ',
+      'state as '];
     const isBlockStarter = blockStarters.some(s => line.startsWith(s));
 
     if (isBlockStarter && openCount > 0) {
@@ -482,6 +483,12 @@ function parseMemberBlock(lines: string[], startIndex: number): MemberNode | nul
   if (firstLine.startsWith('state {') || firstLine === 'state') {
     return parseStateBlockMultiline(lines, startIndex, startBraceCount);
   }
+  if (firstLine.startsWith('state as ')) {
+    // Cycle 63: `state as <MessageName> { ... }` form must dispatch
+    // through the same state-block parser so the `as` override on the
+    // first line is captured.
+    return parseStateBlockMultiline(lines, startIndex, startBraceCount);
+  }
   if (firstLine.startsWith('init:')) {
     return parseInitBlockMultiline(lines, startIndex, startBraceCount);
   }