fix(agent-loop): address review — quiet-item parking, meta, discard balance

Resolve six review findings on the unified-send change:
- quiet (wakeup:false) queued items no longer un-park the driver; the
  inbox distinguishes hasWakingQueued (drives the loop, idle/quiescence)
  from hasQueued (anything to dequeue), so a lone quiet item parks at idle
  and rides the next waking send. whenIdle/cancel settle off the waking
  signal, so cancelling a parked quiet item no longer hangs whenIdle.
- SendOptions.meta on queued/steering sends now reaches the durable
  user/message and steering/message (was dropped except on injection).
- a terminal agent/turn-stop that drops pending steering emits
  agent/inbox/discard so the enqueue-dequeue-or-discard ledger balances.
- the loop-authored continuation reason is snapshotted and frozen like a
  public send.
- gen-cordis-api collects exported classes (body-stripped) so the now-
  abstract-class Agent and its transitive shapes reappear in the API
  catalog.

Adds regression tests for each and re-records the affected snapshot.

scripts/gen-cordis-api.ts

@@ -30,8 +30,35 @@ function quote(value: string): string {
 }
 
 /**
- * Collect exported interface and type shapes; omit names declared in multiple
- * packages rather than risk serving the wrong package's shape.
+ * Reduce an exported class to its type shape: drop method/constructor bodies
+ * and property initializers so the catalog serves member signatures, not
+ * implementation. An abstract class (e.g. `Agent`) is a public type consumers
+ * program against, so it belongs in the type closure alongside interfaces.
+ */
+function classShape(node: ts.ClassDeclaration): ts.ClassDeclaration {
+  const members = node.members.map((member): ts.ClassElement => {
+    if (ts.isMethodDeclaration(member)) {
+      return ts.factory.updateMethodDeclaration(
+        member, member.modifiers, member.asteriskToken, member.name, member.questionToken,
+        member.typeParameters, member.parameters, member.type, undefined)
+    }
+    if (ts.isConstructorDeclaration(member)) {
+      return ts.factory.updateConstructorDeclaration(member, member.modifiers, member.parameters, undefined)
+    }
+    if (ts.isPropertyDeclaration(member)) {
+      return ts.factory.updatePropertyDeclaration(
+        member, member.modifiers, member.name, member.questionToken ?? member.exclamationToken, member.type, undefined)
+    }
+    return member
+  })
+  return ts.factory.updateClassDeclaration(
+    node, node.modifiers, node.name, node.typeParameters, node.heritageClauses, members)
+}
+
+/**
+ * Collect exported interface, type-alias, and (body-stripped) class shapes;
+ * omit names declared in multiple packages rather than risk serving the wrong
+ * package's shape.
  */
 function collectTypeDecls(scanRoot: string = root): Map<string, string> {
   const printer = ts.createPrinter({ removeComments: true })
@@ -41,14 +68,16 @@ function collectTypeDecls(scanRoot: string = root): Map<string, string> {
     const abs = resolve(scanRoot, rel)
     const sf = ts.createSourceFile(abs, readFileSync(abs, 'utf8'), ts.ScriptTarget.Latest, true)
     for (const stmt of sf.statements) {
-      if (!ts.isInterfaceDeclaration(stmt) && !ts.isTypeAliasDeclaration(stmt)) continue
+      const named = ts.isInterfaceDeclaration(stmt) || ts.isTypeAliasDeclaration(stmt) || ts.isClassDeclaration(stmt)
+      if (!named || stmt.name === undefined) continue
       if (!(stmt.modifiers?.some(m => m.kind === ts.SyntaxKind.ExportKeyword) ?? false)) continue
       const name = stmt.name.text
       if (decls.has(name)) {
         ambiguous.add(name)
         continue
       }
-      const printed = printer.printNode(ts.EmitHint.Unspecified, stmt, sf).replace(/\r/g, '')
+      const emit = ts.isClassDeclaration(stmt) ? classShape(stmt) : stmt
+      const printed = printer.printNode(ts.EmitHint.Unspecified, emit, sf).replace(/\r/g, '')
       decls.set(name, printed.length > MAX_DECL_CHARS
         ? `${printed.slice(0, MAX_DECL_CHARS)} /* …truncated — full shape in source */`
         : printed)